Hey, all. I've lurked here forever. But I need some help.

So, my roommate on Friday told me she was pretty sure she had SV because she kept having to urgently go to the bathroom. But, she seemed fine, otherwise. Cheerful and talkative. Them, yesterday, she went out to a karaoke bar with friends, also seemed fine. She stayed gone all night, and didn't come back til this morning. Well, I happen to have been having some upper respiratory stuff going on, so I went to the clinic and they told me I have a sinus infection and gave me some antibiotics. So, I texted my roommate and told her, and she was like "Oh, we're both s*, but with different things." So, I texted her back asking her if her tummy was still bothering her. Because, usually, if someone was had SV on Friday, by Sunday they'd be on the mend. But she said she was. But then she was raving about how much fun she had last night.
Then, when I got back to the apartment, she V* in the bathroom (I think.) The thing is, otherwise, she seems fine. She ate two meals today (like, real food. Pad Thai and whatnot.) She's intending to go to work tomorrow. Everything about her symptoms sounds like she's fine, and doesn't have SV. But, she's still having v* and d*. I'm scared, because we share a bathroom, and on top of that, I have this sinus infection that I'm nursing. I haven't been in the bathroom all day, and I don't intend to use it. I've been using the toilet in the gym of our building (down in the basement.) I intend to shower at my university tomorrow morning before my first class. I also went a bit overboard and bought Anti-viral face masks, rubber gloves, and Lysol toilet bowl cleaner (which I've been too scared to even go into the bathroom to use.)
I just don't understand her behavior vs her symptoms. She basically seems fine. Behaving normal. She went to work Thursday and Friday (she said it started Thursday.) She went out last night and stayed out all night. Don't you usually feel like utter crap with a SV?

I also asked her if she thinks she might be pregnant (she's been seeing a new guy), and she says she just had a period. IDK. I'm really nervous, and I'm so afraid to get sick and I haven't eaten, because I'm afraid. And I'm super aware of every single stomach sensation I feel. I'm also thinking of packing a bag and sleeping in the library at my university for a few nights. (I don't really know anyone in the city well enough to sleep over.)