could I be pregnant?

I have been trying to conceive for a few months now. I have one child already. With my first pregnancy I had no symptoms of being pregnant. I would have never known I was pregnant. My periods have always been very predictable, and regular. I missed a period and that is what prompted me to take a test. and it was positive. I had a normal healthy pregnancy .I'm now trying for my second child. I wasn't supposed to start my period until the 2nd of next month, but I have started lightly bleeding about 5 days before I was supposed to have my period. I also have a lot of cramping that I normally don't have with my regular periods. I have no other symptoms such as tender breasts or nausea. from what I read it is possible that this is not my period but implantation bleeding. just curious if anyone has any opinions on if I could be pregnant or not. and if it is implantation bleeding, is it too soon to take a test ?