QuestionMy daughter had sex 2 or 3 days after her cycle stopped. When she had sex, the condom was off when he pulled out. Is she pregnant?
The only reliable way to tell if someone is pregnant is to take a pregnancy test two weeks after her cycle is missed. I assume, however, that you are wondering if the potential for getting pregnant is there and the short answer is "yes."
Since the condom slipped off, it would be difficult to guess how much of his semen spilt into her vagina, but since condoms tend to force semen up around the penis, it is likely that at least some semen was left in her vagina. Technically it only takes one sperm to fertilize an egg.
A woman's egg has to be fertilized in the 24 hour period after it is released. This occurs two weeks before the start of her next cycle. This, of course, makes it difficult to determine since a woman's cycle, especially when she is young, tends to be variable. But let's assume that this month she was on schedule for a 28-day cycle. Cycles are measured from start to start of the blood flow. I would assume that she had a typical five days of blood flow. Add three days to that and she is into day 9. Day 14 is when her next egg would be released, which would be five days later. A man's sperm can survive up to six days in the womb, so there is a possible, though not highly likely possibility, that some sperm might be present when her egg is released. (Each day past ejaculation the number of surviving sperm decreases.)
Now if her cycle would have came early this month, the odds would increase. If it would have came later, the odds would decrease to zero. But you won't know until later.
Even with condoms, a sexually active couple has a 19% chance of becoming pregnant in one year. The reason the rate is this high is because of things like what happened to your daughter. Condoms can be put on wrong, they can break, they can slip off, or contact is made before or after sex without a condom. There is no such thing as safe sex. Couples engaging in sex must always expect that there will be a chance of pregnancy.
You didn't mention if your daughter was married to this man or not, I hope she is. If she isn't, pregnancy isn't the biggest issue. She and the man would need a serious talk about the state of their souls. "Marriage is honorable among all, and the bed undefiled; but fornicators and adulterers God will judge" (Hebrews 13:4).