girls I need some help, this post may be abit grim but I don't know what else to do!

Me and my ex partner slept together while I was on my period (disgusting I know) and after, I was ill and thought I was pregnant but the test came back negative but either way we broke up, now I've been sleeping with someone new and was EVERYDAY during ovulation, I stopped ovulating two days ago and my next periods in 12 days, but I've been feeling nauseous and had blood red discharge start today, including light belly cramps and they're really uncomfortable, what's happening someone help a girl out 😫