Unless you had in your possession only enough to get stoned, for instance, one modest joint - in which case you arrive in Virginia not in possession ... and you have yet to supply a Virginia statute that makes it illegal to simply be stoned (as opposed to being stoned AND operating a motor vehicle).
I’m not your defense counsel but the first thing he’s going to say is ‘of course you knew this stuff was illegal in Virginia’ and you’ll say something dumb like ‘i didn’t have none of that on me’ and he’ll say ‘the dog alerted ~ don’t lie to your lawyer’
http://medvinlaw.com/alexandria-virginia-state-federal-criminal-defense-lawyer-attorney-law-firm/virginia-drug-laws-penalties-defenses-charges-a-defense-lawyers-explanation-of-possession-and-distribution-laws-arrest/ ~ and you don’t want to ever get caught intoxicated (demonstrable by behavior) because they can stick you in a detox unit rather than arrest you.