Fertile week

I'm so confused. These ladies are on saying they had sex every week there fertile week. That's at least a good 5-7 days. Right? How are you doing that?! My vsgina starts to hurt after like 3 days in a row. She gets sensitive and alittle raw I guess. It's bearable and we can still do it but not very comfortable. Do you just keep on thrusting and ignore it or am I the only one who gets this?