What should I do?

My period has been off for a week but for the past couple of days I have been spotting and having stomach pains. Sometimes I feel nauseous, other times I don't. I haven't been sleeping well nor eating. I've also been having vaginal pains that are sorta like cramps. I've had sex but we've always used a condom. Should I be worried? Do I need to go get a pregnancy test? Is it just because I'm ovulating? I'm 20 years old and I'm a little scared. Can someone help me figure this out and what I should do? -Thanks 💙