Just looking for some advice please.
I am 37 and DP is 45. I'm having some signs of the beginning of peri like more sweats in lead up to period, joint pains, more dryness, which is worrying in terms of TTC. I am prone to UTIs and the fear of them plus DP working long shifts and teenagers and MIL in the house, mean we can't dtd regularly, so trying to time things is probably important, especially given our ages. I can't have sex more than once in a week or I seem to get a UTI, and we need to time it for ovulation, and when neither of us are working, and no teens or MIL is around, which is difficult !!
I've tried OPKs but although line darkens, I never seem to get a darker line than control 
. Even when doing tests twice a day.
I think I am ovulating though, because on day 13/14 I get definite egg white mucus, more interested, higher body temp, and stabbing pains on one side or the other. Usually peaking in the evening on day 14. Then gone 24-48 hours later.
Some months I am not getting my period until CD day 32 though, although I get cramping and PMS for days before. This would mean an 18 day luteal(??) phase I think. Is this too long? Does anyone have any idea when I should be trying to aim for?
thanks xx