I had protected sex from 25th to 28th June. On one occasion, there was unprotected penetration for about 20 seconds at the very beginning before the condom was used. I am currently on my second pack of Dronis 30 and have taken every pill at the same time each day without missing any doses. I have three active tablets left in my current pack. Is there any possibility of pregnancy in my situation? If a small drop of semen may have entered the vagina, would there still be a chance of pregnancy despite taking Dronis 30 correctly?