My Last Period Was Feb 1st Thru The 7th, I

My last period was feb 1st thru the 7th, I had unprotected sex feb 14th, I began spotting the 15th thru the 17th....I havent has a period since...I took hpt and blood test all negative but still no period...today I'm 22 days late for my period...I also been cramping for a few weeks with no bleeding nor spotting..what's going on I'm pretty healthy.