Hello and welcome to HCM,
Before answering your query, I would like to give you brief information about the usage of OCPs:
1. OCPs when taken regularly are very effective in birth control.
2. Some antibiotics decrease the effect to OCPs, so while using these antiobiotics, an additional method of contraception
3. OCPs regularize the menstrual cycles and decrease the blood loss during withdrawal bleeding.
If you are doubtful of pregnancy
, please confirm it or rule it out with pregnancy tests
Since, you have taken antibiotics (typr not known) there is chance of pregnancy.
However, the scant bleeding that you had is not indicative of pregnancy.
Thank you and take care.
Dr Shailja P Wahal