we didn't have sex and I took plan b...

Hi,
Welcome to ehealthforum,
If you have taken emergency contraceptive pill within 24-48 hours of intercourse, chances of pregnancy can be ruled out (provided you were not sexually active after taking it). Withdrawal bleeding usually occurs within 5-7 days of taking emergency contraception indicating that it has worked (it may not occur if the pill is taken close to period). Wait and watch for your withdrawal bleeding/periods. Look out for development of any other new symptoms if pregnancy is suspected. If periods do not start within 10 days of expected period dates, or if you get abnormal periods, or if you suspect chances of pregnancy, consider visiting your doctor/gynecologist at the earliest for thorough examination (to confirm pregnancy related changes/signs in body) and blood/serum HCG level test (to confirm/rule out pregnancy accurately). If pregnancy gets ruled out, and if you are not ready for pregnancy, but intend to remain sexually active, you should consider visiting your gynecologist to get started on suitable regular birth control measures to be protected (after your periods). Be regular with birth control use as instructed. Avoid having unprotected sexual contact if you are not ready for pregnancy. Be in regular monitoring and follow-up with your treating doctor/gynecologist and report any new/abnormal symptoms immediately. Take adequate rest. Drink plenty of water. Maintain healthy diet.
Take care.