Brown spotting after sex possibly around ovulation

[ALB1266]

So we have been trying to conceive for around 2 years and I thought my periods were becoming more regular and there seemed to be positive signs I may be ovulating. Currently I am cycle day 18, usually signs of ovulation are around day 18-22. Last night we DTD and this morning I have woken up with watery brown discharge. My LH test this morning is darker but still low, could this be a sign of ovulation coming? Or more likely to be issues with hormones?

Thanks for any help.

Have clinicians advised why it be taking so long to conceive? Perhaps it's linked to the spotting you're experiencing.

If you have a long a drawn out cycle, that could explain the early spotting

We are under the fertility clinic. And they aren’t really sure as tests and scans seem to be normal but I don’t seem to be ovulating for some reason. Looking to possibly start Letrozole soon. My cycle does seem to be around 35 days.