Hello,
Since you had intercourse on taking the last 21st pill and the inactive pills are to be taken during which withdrawal bleeding occurs, chances of pregnancy are very less. But this depends on whether you missed any pill in the middle or had unprotected intercourse then.
I hope it helps. It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.
Is it the type of pill you take for 21 days and then have 7 pill free days?
If so, as long as you took all your pills during the last 21 days you should be fine. With this type of pill you are covered for the 21 days that you take the pills and the 7 pill free days as long as you take all your pills.
Do you have the leaflet that came with the pills? All the info will be there. If not you should find the information online and read all the details. There are new drugs coming out all the time so it's important to get the info about your particular pill. Google it if you don't have the leaflet. It should put your mind at rest.