Welcome to HCM.
If your periods are of 30 to 32 days, 21 will be a safe period the chances of you being pregnant is very slim.
As you have taken the contraceptives, chances of pregnancy
further decreases. I advice you to wait till your expected date of menstruation
and if it delays by a week you should do a urine pregnancy test using the kit which is available in most of the drug store. Preferably use early morning sample of urine.
I advice you not to perform the test now only as the chances of false negative result is high.
Hope I have provided the information you needed.
Wish you good health. Take care.