Feeling sick/nauseous during sex

hi, girls! so tonight, my boyfriend and i were getting pretty intimate, but during sex itself, i just felt sick and we had to stop because i felt terrible! does this happen to anyone else? im thinking i just got overheated or dehydrated. the high was 98 where im from today, and i spent a lot of the day outside, in addition to drjnking less water than usual because i just got busy, so i was really sweating out the liquid i was putting in my body. what do you guys think? i want to add that i don’t think i’m pregnant, i’m on nexplanon and didnt have sex for a month before tonight