i only had one period when i got pregnant with #2. here ill tell ya that i had my first period january 23rd. the conception date for the second baby was march 5th (we know this for two reasons, for one, that was the only day we didnt use protection, and for 2, she was born november 29th:)). it is possible to ovulate 2ice in a cycle even though it usually doesnt happen, but when your cycles are all messed up like they are when your periods start up again its not all that uncommon. just wait n see, maybe get an ultrasound as they are very accurate to date in the first trimester.