It is actually not "probably" pregnant after 18 days of high temps. It is "you ARE pregnnat" 18 days after ovulation if your period hasn't started. You can actually test before that. Usually a lutal pahse is only 14 days. Most tests you can test the first day after you missed period. How long is your lutal phase usually? If it is 14 days then test 15 days after ovulation. Or just wait the 18 days and you don't need a test
I got a + after only 11 days past ovulation with one my kidlets. It depends on the test. I saw a chart online once that showed how much (or how little) of the hormone different tests could detect. I wish I still had it. You would be surprised. The more expencive tests are not the best ones out there either. I think the one I tested on (the 11 dyas PP) was one I got at Wal-mart. Their generic brand.
I am in the same vote you are right now. It has been one week since ovulation and I think I am pregnant. I hate waiting. I really do!!! I might test in 4 days and then if I get a - then test again in another 4 days.