This is a hard question to answer. Mike Smith grows a lot more fruit than I do and may have a better answer for you than anything I can come up with.

A month is not that long in the overall scheme of things. Were these in containers or ball-and-burlap? Without knowing the number of chill hours of the specific apricot variety you have versus the chillhours of the other trees, we'd just be guessing. And, we'd just be guessing anyway since we have no clue what, if anything, the nursery did to try to ensure the trees got enough chilling.

The only way I know of to try to determine if it is still alive would be to very gently (using your fingernail, not a tool or knife) make a small scrape along the trunk to see if you see green tissue beneath the bark. This might not be good for the tree itself, but a small wound should heal quickly, and the absence of any green is something I'd find worrisome.

Also, much depends on how far north you are in OK. I'm in extreme southcentral OK and our fruit trees are very far along already, largely because our nights are nice and warm. If you are still having nights in the 30s or low 40s, the tree might be slow to wake up.

One worry about nursery stock purchased in late winter/early spring is that you have no idea if they kept it well-watered in winter so the roots wouldn't dry out...or not. I won't buy any dormant tree in late winter unless I can see tiny buds forming on it, which generally means it is still alive.

I wouldn't wait longer than 1 more month. Two months would be way more time than a dormant tree ought to need to wake it up. If the nursery has a 1-year warranty on purchased plants, you have nothing to lose by waiting. If they don't have a warranty like that, I don't think I'd wait more than another month though.

Stone fruits are disease prone, if you see other Apricot Trees in the vicinity come into bloom and leaf out fully while yours still has done nothing at all by then assume it is kaput.

Thank you! We are in the Oklahoma City area, not too cold. I don't know of any other apricot trees nearby but my few year old peach tree already has large leaves and small peaches on it (on the second picture).

I did the suggested scratch test and it is definitely green!! (on first picture). I will be patient for another month. Maybe the poor apricot tree just got shipped here from the North or the nursery just took it out of their freezer when I bought it

This apricot was sold in a biodegradable container. I never tried one of these cardboard-like pots before, I hope that it will actually biodegrade in our clay soil. A couple other fruit trees that I ordered at the same time last month from a California nursery came mostly barerroot and heavily pruned back and those seem to be more vigorous and are doing really well so far (I just hope those trees will also end up liking it here)