Late,breastfeeding..Blah!

I'll try to keep this short period was on  September 17-19th. I had an almost positive ovulation test on the 8th, but I don't know if i ovulated on the 6/7th or if it was later then that. I am breastfeeding, and we dtd on the 7th unprotected. The month is almost over, and I still haven't gotten my cycle! 
Iv tested a few times all bfn..anyone have any advice?