18/f--I've become forgetful, and it's hard for me to focus during a conversation. Is there something wrong?

I'm an 18 year-old female who doesn't have any history of mental illnesses in my family--as far as I know--but for the past few months, I've been forgetting long term and short term memory facts, as well as being unable to concentrate during conversations at times. Is there something beginning to stew, or am I just paranoid? I don't want to jump to conclusions.