What's wrong with my girlfriend?

she on her period normally for about 3 days but ever since she's had an increase in hunger and a numbness in her head and heart palps as-well. She's 16 so i attributed the hunger to her maturing and her irregular sleep schedule but the head problems and the heart rhythm have stumped me. she thinks its emotional problems such as anxiety which makes sense since she has severe family issues. we have/had sex both protected and unprotected prior to her period so the thoughts of pregnancy scare the hell out of both of us. please help only, no snarky or sarcastic answers. im so worried about her :(