Valve says that you can't check your trust factor level... That is of course not true. An easy way to check your trust is to go to faceitfinder.com and write your steam id in here. After that you can hover your mouse on the green field (or gray field XD) under your profile picture to check your trust.
As you can see my trust level is nearly 100% Write in comments what trust you have! And if the guide was helpful you can write +rep and give an award on my profile! Thank you.