Bleeding between periods when i eat feel really sick. i had sexual actitvy but penis and vagina never went fully went in?

Multiple issues: Presume you are not taking/using hormonal contraception. Very unlikely you are pregnant with no real intercourse. Bleeding in-between periods is quite common in young adulthood...result of hormonal fluctuations. Can be evened out with birth control pills which sound like that could be a good idea! Nausea (?) after eating could be stress, but you say you have reflux. Work with doc on treatment.