Hi,
I am 40 and currently 6 weeks pregnant. I have to older children (10 & 13 years old) I found out I was pregnant last Christmas but sadly miscarried in Feb. Cut a very ling story short I ended up having surgery in April.
I ended up buying a Clearblue Advanced Monitor where it reads low - high - peak ovulation. I then started taking baby aspirin each morning from the beginning of August (still taking it now) as well as taking guaifenesin when the monitor read high till it read low.
I honestly think that's what helped me.
Good luck to you, I hope the above helps x