chances are less but not impossible
I have read your query. You had sex on 21st January, that was too early for you to ovulate immediately after the surgical abortion
. Hence, the chances of having conceived again is very less. Also, the fact that you started taking the bcp the next day onwards, make it even more unlikely to be pregnant.
There is a reason for your worry of being pregnant again; I understand that. In such a case, the only reliable method would be to undergo a check ultrasound
scan now, to see if you are pregnant or not.
Wish you good luck.