That cow/milk thing is no joke. Too many girls think that marriage is the natural progression from cohabitation and it isn't necessarily the case. Watch the excuses mount. Money. Job. Better apartment. House. New job. Grad school. Money.
Past that, if a guy has doubts, heed them. Pushing anyone into marriage produces a built in excuse of - I told you I didn't want to get married and x and y are your fault.
I am kinda Old fashioned in this personally , I don't feel a woman should ever push -for an engagement or marraige , but she has the right to NOT do certain things, so the man will then WANT to take that next "honorable" step.
In a way -it is a test, to see where his priorities fall. If you would rather be at least engaged BEOFRE You move in, I wouldn't move in. Or you desire even a wedding date planned and in the making before you move in, then wait until that comes to fruition.
He may not like it-- the change of plans but it may also make him think a little harder about his priorities. Sometimes when someone takes a step back, it causes the other to take a step forward.
How will you feel if you move in and still he does nothing, says nothing, no matter how many hints you throw about others up & coming engagements?
You mention getting a ring on a Credit card, and his making comments about worrying about the money aspect of this.
How does he handle finances? Not all men want to live off of credit card debt -for most of their purchases. Frankly, I wouldn't even allow my husband to do that . I would rather go into a marraige with a cubic Zirconia than a beautiful ring that would end up costing 5 times more because we purchased it on credit.
Are you sure you & he are on the same page on how you deal with money? Maybe he wants /insists on paying cash before he buys your ring. If these are his reasons, focus the most on you both getting decent jobs and paying your debts off , getting in a good place financially, this will ease his stress and if you are truly the one, he will be ready earlier to commit -feeling he is able to afford it .
The financial is a very very important part of marraige. In fact the #2 reason for Divorce- when husbands & wives are not on the same page.