breastfeeding and TTC #2 - anyone?

I got my period back a few months ago, my son is almost 15 months old. We started trying for #2 last month and we had a chemical :( this month I didn't check ovulation very well so I don't know how many days post ovulation I am but according to glow I should had gotten my period yesterday, but because I'm breastfeeding I guess it can be pretty irregular and all my pregnancy tests are negative and I got positives with my son 9 days post ovulation. But not having a period and getting negatives is still really frustrating... :(