Period twice a month?!?!?

Okay so a little background I'm 29, and my period had been very precise my whole life. Every 28 days I'd have it for maybe 4 days. But the last 9 months it has been so weird. The first month when I got my period like normal and then started bleeding again 2 weeks after I thought it was because my body was syncing with my daughter who gets hers about a week or so after I do. Then it happens again the following 3 months. I called my dr and she started me on a bc pill (yaz) said it can take 3 months to start working, some months i don't get break threw bleeding as my dr calls it. But now again the last 2 months it's happening again. I go in to the dr for an in-person visit next week but I'm freaking out a little bit because this is not normal for me at all. Anyone have any idea what could be causing this? Any insight would help.