Alfie Patten - 13 year old father

I was absolutely shocked when I came across this (Alfie Patten, age 13, is the father of a baby girl with his 15 year old girlfriend). Now I'm not going into a big social commentary on sexual education of the youths today and where the responsibility of teen pregnancies lie.

When I was 13, I couldn't even look at boys. They scared me (to some degree, they still do...). Even with the boy that I was crushing on, I couldn't talk to him. I stalked him from the safety of 50 meters. I finally told him that I liked him at a party, after downing a bottle of beer at 16. Needless to say, nothing came out of that (I moved to another city and he was obviously way above my league).

So this brings me to my next question, is it even possible for boys to have sex and impregnate girls/women at the age of 13? It just baffles me (me, the nerdy, virginal, loner and bookish girl).