Can i be preg?

I had sex a few times a few times in sep with a condom, before my period, then during. And i think a day or so after but i cant remember if he pulled out or not. And then about three times this month i know for sure around the begginning of this month he did not pull out and a few days ago he did. Have not gotten my perio yet, but it is irregular so im not sure when it should start. I have recently had a baby he is 2 months now. Wondering if i could be pregnant!! Also, ive been having realy bad headaches and feel nauseas (but that could be because i have not eaten enough here lately). Let me know what you think!!