Period? Pregnant?

I have been pmsing from December 12 - 25, which included back aches, sore breasts irritated etc. Me and my boyfriend had unprotected sex on the 4th and didn’t pull out. My fertile week was the 7th - 12th. The 12th being my ovulation day.

My period finally came on the 26th but I’m still having backaches, sore breast. I thought this stopped once your period came on?

Please help!???