Preggers ?

So my boobs have been sore for weeks 
I'm on day 29 of my cycle but my cycles are irregular last month it was a 31 day cycle. But I've had a 28 day cycle twice before ,33,34,35, and 40. I kinda have a bit of cramps today but I'm not sure if that's due to gas. Could I be pregnant ? And is it a good time to take a first response I've been getting negatives on the cheapy test.