Sexual Intercourse. Less side effects?

Yesterday after me and my husband had sex, he forgot to take out the condom from my vagina. He ejaculated inside the condom but by mistake forgot to take it out and realised after a minute that the condom was stuck inside my vagina. Then i took it out . The problem is now i am scared if there are any chances to get preganant. The semen was inside the condom but when i took it out is there a possibility of d semen to have come out ? Actually i am scared to take a contraceptive pill. I took it once last year in d month of may which was around 10 days after we got married. But i alredy got my periods on that day itself. I dint realise and took the medicine. I bleeded for more then a week. That might due to my first period after our sexual intercourse and the medicine. I have heard lot of side effects about these contraceptives so i am a little worrid to take it again. I wanted to know which one will be d best with less side effects? Can u please tel me d name of the medicine