Say someone has unprotected sex. they end up being pregnant but they don't know it yet. How long after having the unprotected sex would the woman experience pregnancy symptoms? This question isn't for me btw. Haha, I'm just curious.
It could take three weeks, it could take three months. It depends on the person.
Within a month of the unprotected sex. It takes 12-24 hours for the egg to be inseminated, about a week for it to implant in the womb, and then about another week for the symptoms to develop (sore breasts, nausua, vomiting, etc.) Symptoms usually don't come until a bit later though, and some women never have those symptoms.
It can happen days before a missed period OR it could happen months after you find out. For me, I didn't get any symptoms until I was 8 weeks along and by then I had known for a month.