Asking for answers

Kairi

So, I had my period last june 20 and up until now, I haven't had my period. I had protected sex on june 25, 28 and 29. Had spotting (but it kinda looks like a light period) from july 3-10, this is around my ovulation. My nipples hurts now and last week, I feel a bit nauseous and lasted for about 3 days. I'm planning to take a test tomorrow. So, what could have delayed my period?