Community post

The day before O is preferable, because sperm aren't ready to fertilize the second they're inside.
They need to kick around in there for approx. 10 hours to actually mature and be able to fertilize. That being said, eggs are supposed to be good for 12-24 hours. So as long as you dtd as soon as you can after getting a positive opk there's a good chance you'll be ok with timing.

Not to mention the fact that a positive LH surge on an opk indicates that you'll ovulate sometime in the next 12-36 hours. So if you're using opks, dtd straight away will usually have mature sperm there ready and good to go when the egg releases.

(This is all based on an 'average' cycle though, so it's not the same timing for everyone. Just a general idea :) )

HTH.

Thanks ... I also have been ttc for a few months and primary bd in the evening... most every evening ... however timing may be off ??? trying every other day (dh is not pleased) d8-d15...

I always get 2 days + opk and bd on 1st opk indefinitely in am the rest is mostly pm bd...

no bfp yet :(

good luck....