Honey, you have GOT to stop letting your mother run your life. You're a little too old for this.
Your mother is being too controlling. She is also being selfish. She feels that the world revolves around HER -- and it doesn't.
You must remember that when you married, your husband became your new family, and your responsibility is to HIM. Your mother sounds as tho she is perfectly able to take care of herself. Plus she has your father too. Evidently she can get to her doctors' appointments, etc. without you because she's been doing it! So you certainly don't have to "drop everything" like you did before, and run to her side! I know you feel a certain responsibility to her, but that's only because she more or less brainwashed you!

You are PREGNANT now, and you should be taking care of YOURSELF!
You don't need to apologize, or to go crawling back to your mother. You did NOTHING at all to cause any rift. If she wants to play these childish games, then let her. You've got to teach her that you're not going to play these games anymore. Be the adult, and stand your ground. Sooner or later, she'll come around -- especially if she wants to see her grandchild!
Maybe I sound harsh, but your Mother sounds pretty stubborn, childish and a troublemaker to me. She's got to learn that you aren't going to put up with this stuff anymore. I wouldn't make the first move. But I'm Irish too, and I can be just as stubborn! lol

It just seems that she's been calling the shots with you for a lot of years, i.e. "making" you call her after her doctors appointments, or ELSE. What about her calling YOU after YOUR doctor's appots? How come she doesn't do that?

She's selfish.
I'm sorry you're having these problems. I say just take care of YOURSELF and forget these problems with your Mother. Just let them go, and sit back and relax. YOU and your BABY are the most important things right now. By worrying about these other things, you're just putting yourself at risk, and it's just not worth it. Some family members are TOXIC to us, and have to be treated as such. Your Mom is toxic.
Take good care of yourself my friend. God bless and PLEASE let us know how you're doing from time to time. Especially when that precious baby is born! Best of luck! Gentle hugs, Lee