deca has a long ass half life and it stacks up on you so i'd doubt youll feel anything in 4 weeks of just 300mgs... plus a week or two after your last injection you would have roughly the same blood levels as in week 2 or 3 or so...
anyway, i cant imagine anyone actually "feeling" long esters like EQ or deca (yeah well, EQ gives me a fucking headache so i can feel it, but not in that short of a time, lol)...
i mean i FEEL tren ace or methyltren or orals after injection, but not such a long ass ester... maybe you metabolize quickly, idk