Menstrual cup/endometrium thinning

[Twopairsoftrousers]

Hi, I'm new to this, please be gentle with me!

I would like to know if anyone has experience with a Mooncup/Diva cup or anything similar? I bought my first one about 18 months ago and have used them ever since. I wasn't sure if it was my imagination but I'm sure my periods have got lighter during the last year or so - used to be 5/6 days, heavy for about 3/4 of those days but now down to 4/5 days and only heavy for about a day and a half. Up until a few years ago I would have been thrilled at this! However, my partner and I have started TTC about 6 months ago and nothing is happening. I have been reading about endometrium thinning and factors that might cause it but can't find anything related to menstrual cups. I can't help thinking that this could be contributing? It could be just my age, I'm 42, I'm really hoping not as I never wanted kids until I met my current partner, I would be devastated if I find out I can't have kids now. Does anyone know about endometrium thinning, once the damage is done can it be reversed? I'm so worried and would love to hear anyone's thoughts on this, thanks!