 [ Symptoms ] i am 7 days late for my monthly period i have taken a couple of hpt home pregnancy tests but all came back negative [ Disease ] you can have sex right now but you need to use a condom until you have completed one month of the birth control pills and have a normal period this is what i usually tell my patients you may be protected sooner but at least this way you will be sure remember that the birth control pill only prevents pregnancy not a sexually transmitted disease having your partner use a condom adds another layer of protection against pregnancy and protects you against most sexually transmitted diseases