Here's how baby making works:
Woman has a period. Menstruation.
Some days (or weeks!) later her ovary spits out an egg. Ovulation.
Woman has sex before ovulation. Intercourse.
Sperm meet the egg. Fertilization.
7-10 days later, egg hooks up with the uterus. Implantation.
3-8 days after that, her period is supposed to start, if not pregnant. Menstruation.
If no menstruation, woman takes a pregnant test. Positivation. (Yes, I made up a word.)
So if you don't know when ovulation happens:
-You can't guess when implantation happens.
-You can't guess when menstruation is supposed to happen. You might be 'late', but you might not be.
-You can't guess when the pregnancy test should come up positive.
You can guess. It's allowed. You can guess based upon your last cycles. But it's just a guess.
We can't tell you:
-If you ovulated.
-If the egg was fertilized.
-If the fertilized egg implanted.
-If the test should be positive.
Charting will help you determine some of that. OPKs will help you determine some of that too.