3 mc in last 14 months

Steffi • Have 3 amazing children. 2yrs-14yrs . X
Hi. So I've had 3 mc in 14 month all at around 3 months period is always bang on 27 days. Now it's day 33 tests all negative. I'm 45 in 5 days so hoping this is not the start of menapause. 
Exercising and dieting but putting on weight having blood tests done!!! 
Feel low. Hugs x