Do I have a high chance of pregnancy?

I missed 4 days in a row of my ortho tri cyclen because I had no way of getting them.. and on the first day that I missed my pill me and my boyfriend had sex and the whole 4 days after that I have not been able to take my birth control  Until tonight I finally have them. Also I have to take an antibiotic everytime after I have sex and I had to take it the day I did not have my birth control, do I have a high chance of getting Pregnant? Thanks:)