Can u get pregnant just on ovulating day.. Mine was 25 had sex before on and after. What's my chances.. Then on 20 and 21 of this mth?

Yes. The most fertile days to have sex so that a woman or girl can get pregnant more easily are: the 3 days before ovulation, the day of ovulation, and the day after ovulation. Exact chances for one woman? Nobody knows. Nobody can tell. That's how life is... never exact.