Totally fine dude! Most of us do that on a routine basis (myself included). Just be cautious about accidentally reinjecting micro amounts of oil from the first vial(s) into the one(s) you’re drawing from second/third when you push air into them.
For example, if you draw from test first, then deca, followed by tren last, you wouldn’t wanna accidentally shoot a bit of test into your deca vial, and then a bit of test/deca into your tren vial. While it isn’t of significance for this current blast since you’re using all 3 of the drugs, should you decide to use any of these vials while not on all 3, the cross contamination would potentially mean you’re injecting trace amounts of drugs you aren’t intending to take. Can ignore this if you plan on using all of the gear this time, but still something to keep in mind for the future!