No positive ovulation tests.

This month I ended up not buying the electronic opk, and just bought the one with two lines. Well, anyway, I have yet to get a positive one, and it seems like the line is getting more faint each day. Has this happened to anyone and they were still able to get pregnant? We are trying sex every other day this cycle and using Preseed! We usually have sex every day, but I read that it can cause sperm that isn't mature enough and they usually die fast. But obviously there is no right answer, if there was this wouldn't be so hard! Thanks!