Could I be pregnant?

My boyfriend and I These past couple months I've been gaining a little bit of weight, almost 10 pounds, but it's all in my lower abdomen & my boobs have gotten a little bigger. (I used to weigh 105 and I'm now at 112)
 I also get nauseous randomly. These past few days though I've been getting the feeling of butterflies in my stomach but I haven't missed my period. I just wondered if it's possible to be pregnant and still have a period.  KIND advice would be very much appreciated.  Thank you