HELP!! WHEN DO I OVULATE SO MUCH CONFUSION :S?

hi i have a 28 day cycle like you and i use ovulation tests (my first month using them) and i took the first test on day 11 as it says in the instruction and i got a positive on day 13 of my cycle so i would ovulate between 12 - 72 hours after my positive test. So if you were like me i would problem say between days 11 and 16 but i cannot be sure as every one is different. You might want to pick up some ovulation tests so you can be sure of your body's dates. Good luck xx