At What BMI do Hormone Issues Stop?

I know a lot people talk about loosing their period when weight gets too low, but has anyone experienced constant or nearly constant spotting due to low weight? 

I went off the pill a year ago (my husband and I want to leave the door open for kids at this point) and I have experienced almost constant spotting since January.  I am 5'7" and 110-112 lbs and my doctor said the spotting might be from low weight. 

I have never heard of anyone having spotting due to a low BMI and I don't think I am extremely underweight, but I am wondering if anyone else had a similar experience and if gaining weight helped.  If yes, at what point did things go back to normal? 

I got my weight up to around 115 earlier this summer, but it didn't seem like it was helping and I felt constantly bloated, so I stopped the high calorie diet and now my weight is back down again.  I can gain weight if I have too, but I just want to know that it is worth it!

If your doctor tells you something, wouldn't it be a good thing to listen to them?

Your current BMI is 17.3 and 'clinically underweight' starts at 18.5.... Below a BMI of 19 and periods are most likely to come to a halt because the body determines that it is not in a good enough condition to bear a child successfully.  Add to that the other problems associated with being chronically underweight and malnourished .... vitamin/mineral deficiencies, weakened immune system, loss of bone density (early onset osteoporosis).... and there are more reasons than motherhood for wanting being a healthy weight.

A BMI of 19 for you would be 121lbs and you should add another 5 or 6lbs to that number to be comfortably out of the unhealthy zone.  Yes, it's worth it.

I'm pretty sure ideal BMI or around there-ish for healthy hormones is like 21.5-22 for a woman. I have no period... I have zero hormones. My pituitary is on hiatus.