Hiya!
I never get ewcm...although this last cycle I drank decaf green tea twice a day from the end of AF to O day..and it seems like I got ewcm one day (the only day we DTD in my fertile period). It wasn't the classic clear ewcm, it was cloudy, but it's more the stretch factor than the color. Maybe try drinking some green tea to up your cm? There are loads of other over the counter ways to increase it. If this cycle doesn't take, I'll be trying something else next time around.
Don't worry too much, I did a lot of research since I don't get much and it seems that a lot of women can still get a BFP with little to no ewcm. Preseed can help, it's a sperm friendly lube that you insert using a tube about 15 minutes before sex, its supposed to act like ewcm. A lot of women swear by preseed, although we use it and haven't had success with it. Do some research on it and see if it's something you might want to try.
They say it's better to DTD every other day. Don't wear yourself out, it's only takes one! Sperm can live in your body (in ideal conditions) for up to 5 days.
I think temping is more important than opk's...if I had to choose. OPK's can only tell you that you MIGHT be ovulating soon, it's possible to get a positive OPK and never ovulate. Temping however is pretty fool proof. You see an obvious temp spike after ovulation. However it takes a couple months of temping to know when you Ovulate since it only tells you AFTER the fact.
Download Fertility Friend on your phone and check out their tutorials, they are super helpful. You can also use the web version: https://www.fertilityfriend.com/
I have just stuck to using the free version.