Possibly too much info...

Prior to surgery I have always been irregular with my period.  By that I mean I can go months without it,  and I did for about 5 months before surgery.   However last summer I had it fo over two months straight.   I'm a month out tomorrow and have my period again, the second time since surgery.  Has anyone else experienced this. 

I was irregular before. Like 1 a year. When I lost weight I became regular. I haven't missed a period for over a year.

Extremely regular, despite having an IUD.

Sounds like you could have PCOS and yes its normal to have you're period become more regular when you lose weight. I have PCOS and dealt with abnormal periods and fertility issues over the years but my period has been like clockwork since surgery.

I had been tested for that a few times and all times came back negative even though I have so many of the symptoms.