Advice on OPKs

Hi!

I came off the pill mid August (was on for approx 10 years!) so have only been TTC for a short time. This month I started using OPK’s on CD11 (as instructed by packaging as have avg cycle of 28 days) which showed a negative result (no 2nd line, not even faint) but BD’d that day anyway.

Now, I was then away a family weekend on CD 12 and 13 and forgot to take OPK’s with me (doh!) also no BDing on those days.

On CD 15-17 I had a faint line on the OPK’s which I didn’t have before. Probably worth mentioning we BD’d on CD 15 too. I continued testing daily, now on CD 21 and there is nothing again... so technically have never had a positive OPK.

Anyway, I guess my question is could I have missed my LH surge on day 12/13 and just been seeing remnants of LH on the faint line tests?

Also I know that ideally we should be BDing every 2-3 days in order to fall pregnant but unfortunately it’s just been one of those months where there just aren’t enough hours/energy in the day!

Any advice/opinions/wisdom is appreciated :)