Any advice?

Okay so I’m new to this. I’m not trying to conceive but I’m also not really preventing it either. I’m a single 24 years old women. I ended up having unprotected sex during what I believed to be my ovulation period (not planned). I missed my period but got negative tests. I’ve been nauseous, vomiting, having cramps and back pain. I have this slight annoying pain in my left pelvic side. My boobs feel like they are in fire sometimes and my nipples are always hard. About a week after my missed period (now) I’ve still be sick and I get bad headaches and some cramps. I feel a lot of pressure in my lower area where it’s annoying to sit for to long. I also started spotting after my missed period. It’s like super light only when I wipe. And I’ve been peeing all the time. I still keep getting negative tests so I’m just kinda lost right now. I read that I might have ovulated late so I think I’ll take another test this weekend to see what happens. I’m just afraid it will come up negative again and I’ll be back to square one wondering what’s wrong.