Even though I'm taking a Vibin mini and there's been ejaculation in mygina, can I be pregnant?

Good morning. For three months I regularly take vibin mini tablets. Yesterday I had contact with my partner's penis did not put it deep into me as it was already gently because it was my first time and if he did it deeply it would hurt me. We tried to put it in earlier, but with a condom this time we did not use it. After a while my partner came but they howl the penis out of the area of my and the sperm came out on the lower part of my back and a little bit on the buttocks. In addition, I mention that I am three days before the period so I should now have infertible days. Despite the fact that I take medication, full sex did not occur and in addition I have infertible days is afraid that I got pregnant. Is it possible?