Yes there is a risk.
He should stop having sex underage for starters as the fact neither of them considered to use protection shows they are not responsible enough to make the decision to have sex let alone end up with a baby.
If she does end up believing she is pregnant and tries to go to the doctor for a test her parents will be informed. The best bet to find out when her next period is due is to take a home pregnancy test, if she does find out she is expecting and wants a termination again her parents would have to be informed and may have to give consent if it is a procedure she has to under go instead of the pill.
There are these websites they might find informative too:
http://www.condomessentialwear.co.uk/
http://www.ruthinking.co.uk/
http://www.netdoctor.co.uk/sex_relationships/facts/safesex.htm
With regard to termination and teen pregnancy:
http://www.childline.org.uk/Info/SexHealth/Pages/Pregnancy.aspx?gclid=CI6bksmNhJgCFQsMGgodIzdoBw
http://www.womenshealthchannel.com/teenpregnancy/index.shtml
http://www.womenshealthlondon.org.uk/leaflets/pregab/pregab.html
http://www.bpas.org/bpaswoman.php?page=18