My girlfriend and I had protected sex last night using a condom. However, I ejaculated just 1-2 seconds before I pulled out and there might have been a leak in the condom as I saw one drop of my semen near the bottom end of her vagina. I immediately wiped it using my finger and then she washed herself clean. Please suggest if she should be taking an emergency contraceptive pill. If yes, what would the side effects be?