HELP!!! Scared and Worried :(

Hi Ladies, 
I really, really need some help... 
Here goes...
Let me begin by saying I do not have children because I put off having kids  for when I believe would have been the right time for me; in my 30s. 
When I turned 35 last year, on the very month I turned 35 everything changed for me in reference to my cycle. 
1. I went from having a 30 days cycle to a 26 days cycle.
2. I started experiencing lower abdominal cramps a few days before my period, something I have never ever experienced before. I was one of the girls who never understood what other women spoke of when they said they were having cramps. 
3. Then I started spotting 3 to 4 days before my actual period begins.
4. Off and on, started experiencing nightly hot flashes, every other month a couple of days before my period begins.
I have gone to two GYN, have had test done and all returned normal... yet I continue to experience these changes. Well the cramping stopped for about 4 months but started again when I turned 36.
I am terrified that all these changes will impact my chances of conceiving and actually bring my baby to term. I am about to start TTC..... has anyone experienced this????? 
I'm desperately looking for some comments, responses anything that may share some light on what I am experiencing and give me some hope. 
Thanks Ladies :(