Hey
check out the natural family planning thread. It looks like a lot of info, but I was very detailed so if anyone wanted to actually begin practicing birth control through natural family planning, they would be able to.
You've probably heard about it, and heard that it doesn't work. It's actually as effective as birth control (99%) and it's free, it's *drug* free, and it only takes about two minutes a day to observe the symptoms.
There are hundreds of thousands of women who have used natural family planning, for one reason or another, successfully for several years, many near 20 years.
Basically, when you are about to ovulate (the time during your cycle when you can get pregnant) your body shows three symptoms: a change in your cervix, and change in your cervical mucus which makes your vagina very fertile for sperm, when it is otherwise very hostile/acidic, and a change in temperature.
By observing these symptoms every day, (like I said it only takes about two minutes a day, one in the morning and one at night) you will be able to see when they change, and be confident when you have ovulated. You are fertile during your cycle right after your period and usually for 4 days to two and a half weeks, depending on how long your cycle is. But even if you have irregular cycles, these symptoms *always* happen, so you can be sure. And after you have ovulated, which you will know by observing these changes, you can have sex as much as you want, whenever you want, without fear of becoming pregnant because you have already ovulated--there's nothing to fertilze--until your next cycle begins (that is, the beginning of your next period, usually about 2-3 weeks, depending on your cycle). You can even have sex into the 2nd day of your period, the 3rd if you have a longer cycle (28 days).
Some people think this is too much to deal with, but in your situation it is definitely an option that is safe, effective, cheap, and worthwhile considering. There are several books on this form of birth control if you're interested, and i'd say, considering your situation, you should definitely consider it. One is called "the art of natural family planning" and another is "taking charge of your fertility".
You can also use other forms of barrier protection (condom, diaphragm, etc.) during the days after your period when you are fertile, until you know you have ovulated. This is a bit risky because condoms, for example, are only 75% effective. But my husband and I do it, and we're not ever had a scare (we've been using natural family planning for about a year now).
Check out that thread and let me know if you have any questions. There are also several other women on this board who use this form of birth control, so ask away.