Being suspicious is a reason alone for them to search you.
If they smell it, they'll search you.
If they see something that looks like drugs (like putting a baggie in your pocket and a cop saw you) they'll search you.

I've never been in trouble with drugs in my life..
You just gotta keep it the fuck outta sight.
Stop sweating and eyeing the cops, they'll know something is up.

Basically just think like a cop.
They don't mind breaking the law in order to arrest you.
Just like how we don't mind breaking the laws.
Cops are humans too, they're not all robots that try to follow every single order. They WILL persist and persuade.
It also heavily depends on where you live. What state you at?
Living in Manhattan.. man, it's practically legal here lol! Even cops smoke up.
But say, Texas then they'll probably chase you down and beat you up cause you wore a hat with a pot leaf on it.

Just walk past them with a smile. It's probably better to see a cop than not see one, they really do keep the areas safe. There's so many cops in Manhattan that I actually smile as I walk past them knowing the day in Manhattan is gonna be another safe day with the dudes in blue around.

Once again, what state you at?