Maybe I'm a nit but I fold pre...mostly because of this exact situation you are now in.... OOP and not sure what to do and where you stand.
Turn is an easy fold....I mean you have mid pair and up+down on a flushy board so you won't feel good hitting a heart that makes your strait.... not to mention you aren't likely to get paid by the original raiser (MP1) if you hit because he'll fear that either you or BTN has a str8. Just fold it and get acclimated to the table.
OOP FTL