2 periods

Last month I had a period in the very beginning of the month and then one at the end, I don't know if I should be worried or not. I'm not on b.c, I'm still waiting for the doctor to call me and set an appt. But my bf and I use condoms and that hasn't failed me yet. I'm worried about it and have yet to get a period this month. Has anyone else experienced anything like this before?