Can an unattended laptop be bugged without symptoms? Micro-sized exploits?

I have a very shady roommate in my household...she openly talks about cheating others and words it in ways as though it is legitimate.

Is it possible for her to bug my laptop in a way where I would never know and that antivirus wouldn't detect it? I mean I visually look at the outside of my computer for obvious *visible* hardware exploits and don't see any, but are nano or micro sized bugs possible?

She knows I own digital assets. And I haven't logged in to anything for 3 months now in fear she might have done something to my computer. I wouldn't put it past her to hire a hacker. Shes very sophisticated.

I should probably just get a new computer and guard it but would still appreciate input on the matter