Please help...do you think I could be pregnant?

BF and I have just started to tryour luck. This is month number 3 and i'm 3 days late. I have already gotten two BFN, the last taken yesterday morning. I havn't been getting my usual cramping that comes with AF, but have been feeling pains on both right and left sides every now and then. I have no other symptoms. My last period was Feb 25th for 4 days. I have a regular 28 day cycle and never late. But i'm stressing waiting for a BFP or AF, maybe that the cause for late AF. What do you think??