I gave birth April 25, 2012. I believe my period returned June 6, 2012 and lasted about 4 days until June 10, 2012. It's now July 12, and I have taken 3 pregnancy tests over the last ten days, including today which is 6 days past my due period. Could I be pregnant and the tests are incorrect or would they have definitely picked up by now being 6 days post missed period. Or are my periods just not regular yet from having been pregnant only 2 1/2 months ago.

If your having sex there's always a chance you could be pregnant, however it's very unlikely your periods would be back to normal so quickly. On the other hand it could still be early to test. You'll have to wait an see if you miss another period, or you could go in and get a blood test. That might be inconclusive though since there could still be HCG in your blood... at 3 months post partum I still had enough in my system to get a faint positive. Just wait and see if you miss another period and try not to stress because that could make you later.