cramping after sex??

Alright so, me and my boyfriend had sex 3 times today. The first two times we were fine but the third time I felt cramps and a little vaginal pain. Is it from like repeatdly having sex or is it something else? The first 2 times felt nothing and now I have a little pain. There was a good amount of time between the second time and the third time, we went got food chilled a little and then we did it again 🙈 Just wanna clarify if this has happened to anyone before!