Need advice/some kind of support please. Scared of potential pregnancy with hookup and going through mental heath crisis.

I’m really sorry that this is very long but I wanted to provide context. I also don’t know where it’s best to post this (sex, or dating advice, or whatever else, maybe someone can recommend where I should post it). I fucked up really bad and did the dumbest thing imaginable that I deeply regret so much, but I’m mentally breaking down over it now and it’s getting worse every day and don’t know who to talk to. I broke up with my ex maybe a month and a half ago or 2 months now (of almost 5 years), so I’ve been on my own and thinking about other girls and so on because the last year of our relationship I felt like we were already kind of broken up. A girl I don’t know really well and I went out together with her friends to celebrate us completing a class together; we didn’t get close or anything during the class it was just something we were doing together but towards the end of it we got a little flirty. At the end of the night that we went out we both got really drunk and she says she can’t go home because of her mom and wants to come to my place, I’m fine with it of course because I’m fucking stupid and drunk even though I wasn’t really that into her but was being adventurous or whatever. This is only the 2nd girl I’ve ever slept with, I’m a huge introvert who went through depression when I was younger, inside all the time, etc. and wanted to try something I hadn’t before.

We have sex at my place (edit this was on Sunday Oct 30th, something I forgot to mention), I start off with a condom but we’re both drunk and into it and we both agree to take it off midway. I’m 95% sure I DID NOT cum in her (I didn’t feel any orgasm and there wasn’t anything “leaking” and so on), I kept pulling out and stopping whenever it got too intense. That being said I’m sure precum came out at some point or multiple points, and I know it’s technically possible to get someone pregnant with precum. I don’t think much of it that morning because I’m still super drunk and hungover until I start thinking about it later in the day and becoming filled with dread over this.

I basically say all of this a few hours after she’s left to her place and let her know I’m really anxious about this, and if it’s possible for her to take Plan B or something similar, that I would pay for it of course and it’s just to be safe. She says don’t worry I’ll monitor my period that she should be getting it within a day or 2 and I start to get more nervous because she won’t just take something that could immediately stop the issue. Then I ask when was her last period and she says October 1st. I eventually get to asking about hypotheticals and if she was to get pregnant would she get an abortion? That I would be there every step of the way and pay for everything and so on which I absolutely would and she says shit like ‘don’t worry I have no expectations I don’t mind raising a kid on my own’ and I start freaking out. I’m trying to keep it cool so I don’t get her upset but I keep pressing and asking what are you talking about and I keep telling her I would be financially and emotionally responsible like what is she talking about basically and she thinks I wouldn’t be for some reason. I don’t even understand the logic of wanting to keep a kid that you’ve had with a relative stranger. I asked if she’s against abortion and said she’s not but that she’s ‘too old’ to do that kind of thing now that she doesn’t care she’d just raise it that her mom was able to so she could (she’s only 31, I don’t know what she means).

Eventually I keep pressing (this is all through text and call), and she just keeps being extremely cagey about the idea of abortion, saying that it’s basically impossible to get pregnant because she’s going to have her period soon and the window would’ve been a couple weeks ago and that she’s not worried at all. I try to explain it may be unlikely but it’s still possible and want to like please just cover ourselves you know. I keep trying to explain this is very serious to me and I’m getting scared about it that would she please consider getting one if it got to that point, she says something like ‘fine i will’ and I ask if she’s just saying that to make me feel better or if she’s serious about it and she basically says it’s just to make me feel better.

I know this whole story maybe portrays her to be like calculating or something but I have to believe she’s not, she never seemed like that and the positive interpretation is maybe she really is just nonchalant and thinks it won’t happen, but to me being so flippant about something so serious is extremely scary to me and I want absolutely nothing to do with her now. She wants to hang out again and I’m trying to get out of it while also trying to still talk to her just so I can get info on if she’s getting her period or not (but I don’t even know how to verify this!? like how do I know she’s telling the truth about october 1st, or whatever else).

So it’s now November 2nd and she said she still hasn’t gotten it, I know it can be a little more or less than the standard 28 days but I’m getting more and more scared and hopeless. She says one time she didn’t get her period for 6 months or something because of stress and another time for 3 months, and she’s like being really flippant about it and joking around and saying like ‘sorry I’m joking around about it I know I’m probably not making you feel better but I just feel like it’s impossible’, but internally I’m really breaking down and don’t know what to do. Having a kid to someone I barely know will emotionally destroy me and I’m scared I would become suicidal even, it’s really something that would ruin me and I’ve tried to communicate this with her (at least the idea of how serious it is) but I’m trying to still be calm so I don’t make her upset because I feel like I’m dealing with someone who isn’t understanding the severity of it.

I want to run back to my ex so bad, who I did love and trust but felt like we didn’t want the same things, but I know she would never ever act like this towards me and we thought the same about things like this. I want to tell her everything and get some kind of potential support because part of me feels like she would understand and try to be there for me but I also know it would hurt her and I don’t want to do that, we both loved and respected each other and broke up amicably (although she wanted to stay together longer and work things out more than I did). I don’t know if I should tell her or not, I just have nobody else to talk to about this and it’s scaring me so much and it makes me miss my ex so much. I can’t enjoy anything, I can barely function without thinking about it.

Can anyone here just please try to comfort me a little about this and let me know it really is unlikely for her to get pregnant at least? I’ve been googling for days but those always bring out the worst, scariest results. I know I fucked up, I’m beating myself up over it so bad every day so I would appreciate if there weren’t jokes or shitting on me, I’m really doing that to myself all day about this, and the fact that this girl isn’t concerned makes it so much worse to me. What do I do? How do I navigate this and get information from her while maintaining my distance? How do I even know if she’s telling the truth about her period? I don’t know what to do and I don’t know if I can last another month without telling my ex. I even asked if the girl would take a pregnancy test in 2-3 weeks and she said she wouldn’t, then after I asked why she wouldn’t want to know she said she was just joking that she’ll do it. I absolutely cannot understand this kind of response and don’t know what to do.

TL;DR version: I had a hookup, didn’t use condom for half or most of it, 90-95% sure I did not cum in her (kept stopping before it, didn’t feel orgasm, etc.) but I’m sure there was precum at some point, the girl is very cagey about or maybe against plan B and/or abortion but I’m not 100% sure and is also very flippant/casual about the situation, saying it’s impossible. Says her last period was october 1st, that she should be getting it this week, hasn’t come yet but she says it’s gone over before in the past. I want to run back to my ex and tell her everything for some kind of IRL support but nervous about her response. I’m freaking out and beating myself up about it so bad and don’t know what to do.