Do you have regular ovulatory cycles? It's possible that your recent weight loss has caused ovulation and/or hormonal changes that are affecting your period.
Before starting the diet pill, I had regular menstruating cycles (am also on BC pill) so this is very new and weird to me. Also, never had any other health issues in this regards either.
I took the pill this morning, but still haven't heard back from dr, and had called again. I am going to stop taking until I can either go in or see my OB. I go monthly to my reg dr to be monitored, and now that I think about it, I've been taking the diet pill for about a month and half. Went back after 2 weeks, and everything was fine, no side effects at all. It all slowly started after that initial follow up.
Losing weight always screws with my cycle. DD is a product of weight loss.