Please Help!!! Slight TMI

Ever since January my periods have been late. I used to have my period precisely at the same time every month for the most part. But everything changed when my boyfriend was here in January and we would have sex often. We were safe and he would always pull out. But before he put on a condom there were times where he would enter but it was extremely brief. I was worried I was pregnant but then eventually after about 10 days I got it in January (heavy flow with clots). In February I was late again and I was worried I was pregnant. So I took two pregnancy tests but both were negative (I even had a friend make sure it was negative and one was a digital one). After that test I immediately got my period. I wasn’t stressed anymore I guess. And my period it wasn’t light. It was a full period (heavy, some blood clots, thick, and when I’d pee I’d be dropping blood into the toilet bowl. Sorry for the TMI). Now, after that period in February I’ve been working out and trying to lose weight. I don’t know if that can have anything to do with it... I am now 9 days late. Can anyone help please? Is there something I could do? Anything will help! Thank you!