Pre Period or Pregnant?

I only just saw this group so I thought I’d repost on here

I had unprotected sex on the 18th of April , only lasted 4-5 mins, pulled out because “he wasn’t feeling it”(pretty sure he couldn’t get hard, his mates were in the room next to us). I didn’t take plan b because i knew he didn’t cum and it wasn’t long enough for pre cum and, at the time I couldn’t afford it.

2nd of May I’ve been having really sore boobs and I’ve been having nausea, cramps and headaches. My period is due on the 4-5th so I wasn’t sure if it was to do with the period or if there was a chance of pregnancy.

I read that nausea and headache are most likely from stress and I have been over thinking a lot about it + with the stress of school but I just wanted some opinions.

Oh and if any of you’s were wondering, no the sex wasn’t good