I am on birth control and had sex 2 days before ovulation and i missed 3 pills the day after having sex a day after ovulation i had brown spotting?

Possibly Pregnant: Given the timing of missing the pills there is a possibility of pregnancy. Take a pregnancy test when you first wake up in the am and if negative repeat in a week and even one week after that. Stop taking the pills at this point and wait to see if you have a cycle, although having bleeding at that times does not compltely rule out pregnancy. Consider yourself pregnant until proven not.