You are in a tuff spot. If you ignore it, you have to swallow your suspicions of use; those feelings will eventually bubble over.If you comfront him, you run the risk of being manipulated into believing that you were wrong....or, you actually follow through. No real great option here.
Laying awake at night starring at the ceiling and wondering about what impact my actions (like this) would have is what finally led me to buying a home drug test. My mind could literally not handle detective work or debating if he was using anymore. Or if what I was seeing was real or if I was just hyper-sensitive to signs. I made my ultimatum, watched my addict slip then introduced the drug test on a sober day. He accepted that it existed in the house from that point on and that we wouldn't be having long or short conversations about whether he was high or not anymore.
Right now, I would surrender to the fact that you aren't sure of what to do and that is okay for tonight. Eating and sleeping always brings better choices and decisions. Let all that crap go for one night and just fall asleep.
I wasted many nights wide awake when the answer presented itself the next day. Essentially, I wasted time thinking when I could have slept and all would have been the same.
No matter what you decide to do, you'll need to be in a better frame of mind to make it work and to feel good about it.