[Brandye]

You want protection. Keep the bare penis out of the vagina. Conceptrol (a good spermicide) is about as effective a a condom, alone, in preventing pregnancy. Using them together reduces the risk of pregnancy to about the same as being on the pill.

Assuming that it takes two days for the egg to traverse the tubes and sperm will live, realistically, up to four days in the uterus and tubes, the knowledge that one in four sex acts during fertility result in pregnancy and a normal 28 day cycle, this would be 6 / 4 / 28 = .14 chance of pregnancy (Hopper, above, has calculated the chance of fertility during a random act of sex; thiss adds the known "failure" rate). Do this thirty times and the chances are better than even that a pregnancy will result.

There are 400 million sperm in each ejaculation. That puts many in there and lots left over to be all through the male system.

A bare penis should not be within six inches of an unprotected vagina.