this is a great piece via feministing about how hard it can be for young girls to buy pregnancy tests. there shouldn't be an age restriction, and legally, there isn't one, PERIOD. there is also no age limit to buying condoms, and i know people have experienced bullshit like "you must be 18 to purchase."
the thing to do is to know your rights and assert them, even if it means acting "like a bitch".
that's my feminist rant for the day. well, so far.