I wouldn't worry about meeting a cop or government agent for a bitcoin deal. Most countries don't have the time or resources to set up such operations. And they are limited with manpower. That's more a thing from movies.
I can see from OP's post history that he posts in the Nigerian local. Let's assume he is Nigerian. It isn't exactly an economic superpower in the world. Their government agencies have bigger fish to fry than catching bitcoin traders in the act. Unless, of course, we are talking about huge sums of money.
I guess you're right. If you keep a low profile, there's no reason for the government to be suspicious about you. Would they be stupid enough to waste resources on a random citizen? I don't think so. Unless you're flagged as a criminal, there should be no reason to be worried about making BTC transactions under the table.
I guess people living in autoritarian countries like China and Russia are already doing this. Eventually, these countries will end up embracing the revolution. All just to fill their pockets with money (taxes). Hopefully, Bitcoin fulfills its mission of decentralizing the economy before it's too late.