My periods come very regularly at the same time every month. I started spotting very lightly late Saturday night which was the day before I was due for my next period. Didn’t have any cramps this month and I usually do. In the lead up to this I also did not have any of my usual pms symptoms. Since I started spotting I have been very tired and slightly ragey/emotional. Should I take a pregnancy test or would it for sure be negative since I am spotting? Is implantation bleeding common?