Period help

So me and my partner slept together on most of my fertile days this month.

My period is usually early however this month I got a dull ache which I never get and when I went to the toilet and wiped myself I had pink discharge it was there on and off all evening so I put on a pad I woke up with nothing, after a little while I had red bleeding much lighter than my usual period and no clots which i always have. The next day everything had gone back to pink discharge and then stopped completely. Thing is a few days later im nauseous alot and im crying about everything. Do you think there would be any chance I could be pregnant or just an odd period?