There is no chance of pregnancy
in dual protection (condom and birth control pill) without ejaculation inside vagina. So don't be much worried.
Pregnancy is possible only,if unprotected sexual intercourse is done with ejaculation around ovulation time in regular period. Ovulation occurs approx 14 days before due date.
Practice safe sex
by using safe period/OCP/Condom etc to avoid unwanted pregnancy & unnecessary vaginal bleeding.