BTW, sorry to hear AF started...but just think...you get to bd a lot next month when you try again!
You should wait a few days and test again, if your period doesn't come and you still get a negative I'd see about a blood test. You may have ovulated late, so the hcg levels may not be high enough to show positive if you are pregnant. What kind of pg test are you using? First Response and Clear Blue digital seem to be pretty popular, and accurate.
the same thing happened 2 me i was days late and it started on the 5th day but i had countless BFN but when i did start it was different 2 the norm not as heavy and no pains but i was reading and some ppl say 1-1 1/2 w3ks late is when u shoud test but also i read that ppl have been 9 and 11 wks b4 they get a BFP but gd luck and lots ov baby dust let me know how u get on oh u could go 2 docs and ask for blood test done there more accurate