I found age did make a difference,
Pregnancy 1 was a happy accident at 20, ended in m/c sadly
Baby 1 first month of ttc after mc gave birth at 21
Baby 2 first month of ttc after coil removed gave birth at 27
Baby 3 first month of ttc after coil removal gave birth at 30
Baby 4 4th month of ttc after coil removal gave birth at 35
Baby 5 9th month of ttc after coil removal gave birth at 37
I only used poas ov tests for baby 4 and 5 when it looked like nothing was happening, with the others i had only to remove my coil and i was pregnant and baby 5 took 9 months, of pre seed, instead cups, ov prediction poas, you name it I tried it, and by 9 months I was going nutty over it.
So for me age seems to have made a difference and i have noticed my fertility drop off.
Just wanted to say also you could try and use poas ov detection for a few months, if you are still ovulating on a regular day each month it sounds promising you are pretty fertile, once you start getting ov day 12 one month, 16 the next it is a sign your fertility is becoming more erratic and so fertility is dropping off, if in any doubt i would start ttc xx