Welcome to the forum, and you are right. Being poly and balancing motherhood and a career are completely different from university and graduate school days. I had to learn that lesson the hard way. The biggest thing to remember is expect the unexpected. No part of parenting is predictable, so whoever you date needs to understand that and be flexible and understanding. They cannot pitch a fit when you have to ask for a raincheck on a date because of a sick child at home. Yes, there are people who behave like that. (I just read a thread where the girlfriend was upset because the OP was helping his partner with feeding their newborn twins. It seemed like she wanted to limit the amount of time he was at home with his new family because it cut in to their time.) Stuff like that? Red flag.
I am sure you will be fine, but read through the various forums, search for poly parenting or similar terms within the forum, and check out the blogs section. There are a lot of parents on the forum, and each one does things differently. Some prefer that partners have no contact with their children while others elect to co-parent the children together. Some tell their children, "This is my boyfriend/girlfriend X, and I love him/her like mum or dad." Make sure that you and your spouse are on the same page about things regarding other partners and children. Especially just how involved those people will be allowed to be. Things like discipline and just how much to tell them seem minor, but children do get attached quite easily. It is always unfortunate when they wind up in the middle of break-ups or start loving a person who later leaves. You have to find the right way to do things, and trust, there is no right way for everyone.
If you have questions, feel free to post them and ask. Other than that, good luck, and I wish you well.
Ry - Me. Panromantic demisexual with a history of polyamorist tendencies. Married to...
Mr. Grey - The once distant stranger that I complement beautifully. DH of 12 years and father of our (3) children.