value betting river

[alphatmw]

this screws me up so much. converters not workign so i'll just describe it. .1/.25 NL

i'm in BB with 75o. flop comes 763. SB bets 1, i raise to 3, rest fold and SB calls.

turn is 7. he checks, i bet about 5, he calls.

river is blank. he checks, i bet, he raises all in, i call, he had Q7.

should i have bet the river or just checked it??? i always figure "if he has this beat, he would have bet" and value bet the river, only to lose the hand.