Period or something else ??

June 3rd I had sex and my boyfriend pulled out . I’m pretty sure he did not cum inside of me because he masturbated in front of me for a little bit then he came on his own . Last month my period was EXTREMELY short and light. It scared me because it’s normally longer than 2 days and heavier. I have been getting a lot of diarrhea, nausea, and cramps. I’m thinking it’s this month’s period coming or it could be something else?? Please need your help!