That is true, but I've known someone who got pregnant while on her cycle. Things can happen. If you're still unsure talk to your doctor about it! Good luck!
Sperm can't live 2 weeks, especially through a cycle, so that wouldn't be an issue at all.
It's very very unlikely to get pregnant while your on your period, a woman ovulates about 2 weeks after her period, so that is the most likely time to get pregnant, I wouldn't stress about it at all.
Yes, it is possible because the length of time sperm can live in your body.