just need advice

i had unprotected sex two months ago and i've had 2 periods when they were supposed to come except my last one just came a day early.. and i'm psyching myself out but i think i'm pregnant but i haven't had any symptoms except i get headaches and i've been wanting to eat more but it's not like cravings. and i have bad sinuses and always take medicine for it so my headaches could be from that. so what's the chance of being pregnant?