Frustrated and confused

I used to take 1000mg Metformin a day about 12 years ago (I was about 15 or 16), but had stopped about 8 years ago (20 years old) when I broke my leg and had to go through several surgeries. I don't know why I was taking them then.

2013 I was 7 months pregnant when I found out that I was pregnant (story of its own). Gave birth to a healthy girl who is now 3.

Mind you I have always been irregular skipping a few months at a time. The past few months have thrown me some curve balls. At some point I thought I might have had a miscarriage.

So...

Aug I had my normal 8 days, heavy bleeding. At the beginning of Sept I had another normal 8 days, not as heavy as usual but still heavy bleeding. At the end of Sept I bled for 3 days. Early Oct I bled for 4 days, this was very light. Then mid to end Oct I had a very heavy bleeding for 1 day. That's when I thought maybe miscarriage. SO and I were disappointed at the thought of it being that. Saw the OB early Nov. OB said it could have been school related stress for I had just started back with school again in May.

No AF in Nov. Also saw an endocrinologist in Nov. Diagnosed with PCOS). Miss Dec bled, but so light no pad needed.

Stopped Effexor (only 1 month of usage) and started metformin mid Dec. Lost 14lbs since. Normally when I lose the smallest amount of weight my AF comes immediately and then i gain more weight.

I would have thought with being on the metformin, and continuously losing weight, and have been eating healthier and adding more exercise to my routine my AF would have been maybe a bit more regular. It's not! I took a prego test last week and it was a BFN. How disappointing.

Today, according to eve, I'm 12 days late. I feel very bloated, cranky and tired. I know I shouldn't complain because I have one child already and there are those that aren't able to conceive. I would really love to have a second child, I grew up miserable because I had no siblings. And I certainly don't want to go a whole pregnancy without knowing it again.