You ovulate 14 days prior to your period. this is pretty standard for most women (there are always exceptions). The number of days before you ovulate can vary between women. Each woman is different. Some can actually feel it when the egg is released. You get a sharp cramp and may even see some spotting that day. Leading up to ovulation, your discharge gets thicker, but still pretty clear. It has a smell, not bad, but a certain odor. It actually is very attractive to men. Men in general behave differently around an ovulating woman. Research has shown that strippers who are ovulating make more money.
Many, but not all, women feel more sexually aroused during this time. Obviously, this is the time you are most fertile. Your skin is clearest and you tend to be in the best moods. The egg only survives 24 hours. After that, it move out of the fillopian tubes into the uterus. Eventually it is expelled with the uterus lining and that is your period.
There are safer periods to have sex, but it is no garuntee. Sperm can live in your uterus for 5 days and you can never be sure when you are going to ovulate. You can ovulate when you are having your period, so you can get pregnant even during your period. Fertility books and tracking can be effective, but the possibility of doing it wrong is so high. You have to measure your temperature each morning before you get out of bed. You can't even move a little around the bed. So your partner has to do it. You can't miss a single day. It actually requires a lot of work. Remember, this won't protect you against infections.
If you are looking to have sex without condoms or being on the pill, there are other options like the diaframe and IUDs. If you have sex trying to figure out your ovulation date, you are takinga risk. Trust me, I got pregnant this way. Luckily I was in a situation where getting pregnant was not a big deal.