Cramps !!! Help Please


So my AF is due tomorrow , and this morning about 3 am i was in so much pain with low abdominal cramps until about 5 am , i still have cramping when i sneeze or sit .. what is this a sign of ??? Should i be worried or am i having pregnancy symptoms?

My Ovulation was the 16 and i BD the day of.

Last month my AF was 2 days earlier . Has anyone experienced this and got a BFP??? Please help