Is during or around ovulation the only time a female can get pregnant?

Yes. Pregnancy occurs when the sperm meets the egg and fertilizes it in the fallopian tubes. Ovulation is the porcess by which a woman releases an egg. Therefore, an egg must be released for pregnancy to occur. Ovulation occurs usually around day 10-17 of the menstrual cycle, with day 1 being the day you get your period.
Yes. If you don't release an egg (ovulate), you can't get pregnant - there is nothing to fertilize. Remember that although period length may differ from woman to woman, it is always 14 days from date of ovulation to period in any month the woman doesn't get pregnant. Also remember that sperm will will wait for an egg (up to 72 hrs), but the egg won't wait for the sperm (gone in 24 hrs at best).