Yes, their first period is a sign that their body is changing, and that it’s now possible for them to get pregnant. For a pregnancy to happen, a sperm cell needs to fertilize an egg in the fallopian tube (for example, during penis-in-vagina sex). If the egg is not fertilized during the ovulation stage, then the uterus lining sheds and flows out of the vagina as a period. Remind your young person that just because they are physically able to get pregnant, doesn’t mean they’re ready to have a baby. If they want to talk about this more, have them reach out to their parent, caregiver, or another trusted adult for more information.