OPK help?!!

[Bubblegum89]

I'm on cycle 2 of ttc. The first cycle I got a very strong positive OPK a day or so before I ovulated. I took an opk last night and it was very almost positive, the line was the darkest it's been this cycle. However I took another one this afternoon and the line was back to being quite faint again. Is it possible that my surge happened overnight and I missed it? I had some mild cramping in my left side for a few hours this morning (I had similar cramps in my right side around ovulation last cycle) so could I have ovulated today? We dtd Saturday, Sunday, yesterday and today and will be dtd again tomorrow so do you think that if I did ovulate today and just missed my surge on the opk that we've dtd enough?

[Dolwar]

Surge can literally happen overnight so yes to your first question. Ovulation is at the peak of the surge. The egg then has to travel down the tubes and into the uterus before being degraded so this can take a few days. Sperm can live up to 72 hours. Hopefully you can do the maths from that about when to dtd!

[Bubblegum89]

I'm terrible at maths haha I've had sex yesterday and today, I'm guessing dtd tomorrow and Friday will probably cover me?