No period for 3 months - negative pregnancy test

[Acidrain]

I had my coil removed in Feb 19 to try for our second baby, my periods returned and where reasonably regular.
I haven't had a period since the end of July and have had 3 negative pregnancy tests.
I'm exhausted, grumpy, no sex drive and my hair is falling out!
I'm in my mid twenties, a little overweight but exercise regularly and eat healthy.
I have no idea what's going on with my body or what to do next!

Peri-menopause is my first guess.

BTW, peri can start even in your 20's. Not common but it does happen. You need to see a specialist, and also have your thyroid tested.

See your GP. I am experiencing irregular periods and my GP has organised a number of blood tests including things like thyroid, vit D and hormonal checks.