I had unprotected sex couple of days before my ovualtion date and a week after I started having this mild cramps, not painful but felt like pulling, prickling, dull pinching sensation in my lower abdomen sometimes feeling it towards my lower back. This was from Sept 28 till like Oct 17th then it went away having it on ocassional days. I didnt have any other symptoms except for feeling a bit tired than usual. I took a pregnancy test on Oct 17th which was negative. My period came 12 days later than usual which was the longest it has been and the mild cramps i had was something I never experienced so definitely something was going on. Would it be possible that I had chemical pregnancy as my period was delayed and felt something new? For reference I am 36 and my husband is 42.