hello,
i can understand your chances.
for your first question, you can be sure of not getting pregnant if you had intercourse with your partner on the first day of your bleeding.
even if the ovulation had occurred(which in itself is very rare at this point unless you have very irregular ovulation), the
uterus is not supportive for
pregnancy at this point of time.
stay assured of not getting pregnant.
for your second question regarding
plan b, this usually works when taken within 72 hrs of intercourse. this has a failure rate of 2.9% which is fairly low. if this intercourse is the one you spoke of in the first question, the chances of pregnancy are almost none.
in case you have missed your period by a few days, i would suggest you a urine pregnancy test done at home just to be sure of it.
hope i have answered your concerns.
feel free to ask further queries.
thanks for choosing HCM