explanation?

sam

Help me figure out what is going on...

I had unprotected sex on cd 5, 8, and 12. ovulation normally occurs between cd 9 thru 11. cycles are always 24 days. on cd 21 I had some light pink spotting once. then today, cd 29 some light spotting that seems to have stopped. All negative hpts...what could be going on? LMP was 4 weeks ago today.