Could intercourse from 9/25 indeed have gotten me pregnant if my doctor put conception at 9/29?

Yes: By many estimates, sperm can survive in the female genital tract for, at least, 2-3 days.

Absolutely!: Sperm can survive in your genital tract for several days (some say even 4-5 days) waiting for ovulation to occur. They can be quite persistent and patient :).

Yes: Possible as boththe egg and speerm can live 3 days.Considered fertile generally 3 days either side of ovulation.