I've been bleeding excessively 3 days after taking plan b. my period is supposed to start june 30. does this mean i'm not pregnant?

Pregnancy unlikely: Taking Plan B or other emergency contraceptive pills can alter the timing and quality of the current menstrual cycle bleeding and of the upcoming cycle. One should check a urine pregnancy 3 weeks after taking Plan B, to confirm nonpregnancy. Home urine pregnancy tests are very accurate, inexpensive to buy, and sold in stores everywhere.