If you normally have a 28 day cycle, you probably want to try from 11-16 days past your last AF. That's because you probably ovulate in the middle of your cycle, but your luteal phase length (length of time between ovulation and next AF) can be between 12-16 days, although it it usually doesn't vary by more than a day or two. In other words, if you normally have a 14 day luteal phase, it will probably never be shorter than 13 days or longer than 15 days. So you could have a 15 day luteal phase, 28 day cycles, and O on day 13...or a 12 day luteal phase, 28 day cycles, and O on day 16.
There's a book called "Taking Charge of Your Fertility". It has tons of information about baby making and will help you with other ways to determine if you're fertile, especially if you have irregular cycles.
The first day of your cycle (day 1) is the first day of your period. So if you have a regular 28 day cycle you are most likely to ovulate on day 14, but your fertile period is between day 11 and 16...since theoretically you can ovulate anytime between those days.
if your cycle is 28 days, then you most likely o on day 14. the general rule is that you o 14 days BEFORE the first day of your next cycle. so if you have a 30 day cycle, then you most likely o on day 16. and so forth.
if you are trying to conceive, it's a good idea to make love every other day starting about a week before you o. so maybe around day 8 or so for you. that is because sperm can live for up to a week in your body and that way once you o, it's right there and ready to fertilize the egg. you should also try to make love on the day you o and the day after, just to be safe!!
hope that helps and good luck.
Yes, its counted from your first day of bleeding, I would bdance from day 10 onwards to about day 16-18 ish just to cover any late ovulation possibilities.
We assumed i would ovulate around day 14, i am now on CD 29 and i still havent ovulated, we bdanced most nights and found it a strain so next time we are going to dance every other day, that way we wont feel as tired and we wont 'kill the mood'
If you have any doubts then try and get hold of the TCOYF book and start temping - this also helps pin point ovulation.