Stopped nursing over a month ago and STILL no period

I breastfed both daughters until a year old when they could have whole milk.  With the first, I got my period when she was 11 months old (still nursing but only twice a day).  The second just turned one in March and I weaned her then, but I still have no period.  I have been calorie counting and exercising and am at my lowest weight ever since high school (I am 27, 5'3", and hovering around 115).  I was always 125-140 and always on birth control and always had regular periods while on it.  When I was off bc pills when trying to conceive, my periods were always erratic but never more than 40 days.  Anyone have a similar experience?  I took a pg test a while back just to make sure and it was negative, plus I think I would know.  Oh, I did get what I thought was my first post partum period at the end of January when my daughter was 10.5 months old but like I said, NOTHING since.  What gives?  Could my weight loss be affecting it?

My period never returned naturally after I stopped breastfeeding my daughter (who is now 4). I stopped breastfeeding her at 6 months and when she was about 14 months old, I still hadn't started my period. My doctor finally prescribed medication to get my cycle going again. Once that happened, I was able to start on my regular birth control pills (instead of the mini pill).

I, too, have extremely erratic periods when not taking birth control pills. I have been that way my whole life. I would go months and months without a period and they never followed the same pattern. I just can't deal with that kind of uncertainty.

I'd say nothing's up but you can always call your doctor and seek their opinion. You're at a healthy weight for your height so it MAY NOT be the issue.