Cramping, no period, ends with BFP!

I have been having bad cramps off and on the past 4 days and kept thinking my period would start. I didn't have any other symptoms except having to loosen the strap on my bra. Now, 5 days past when my period was due, I get my BFP! I'm in disbelief because my husband and I only started trying this cycle and I'm already pregnant! I'm in definitely hasn't sunk in yet!!!