I had unprotected sex just after expected ovulation took ec 14-15hrs later. 7days later brown spotting and abdominal sensations. is it normal?

Yes: However, it could also be implantation bleeding, so check a pregnancy test in a week or so.

Wait a few: Wait a few more days, like 3, and you should be able to take a home pregnancy test to see if you became pregnant from this encounter. You did a great job taking the EC 14-15 hrs after sex. You might want to have it on hand in case that situation happens again so you don't have to wait that long. Taken immediately, can prevent pregnancy if ovulated 85% of time. Take HPT in a few days