I'm sorry you are worried about being tossed aside...but understand you are the rose and the ow is the weed. You've got history w/this man and you share a child. The ow shares nothing but a good time and yes, strokes his ego at this time. She's nothing but a crutch/Band-Aid to his ailing soul.
Yes, you can do something...you can live your life to the fullest, continue being the great person that you are and be strong and independent and be there to support your child. Your child needs you now more than ever because daddy has taken a seat on the Mother Ship and won't be back for a while.
You asked what temp check means and I will give you my opinion on the meaning. Others may come along and chime in w/their opinions on this as well. It's when they come around, phone, text or email you to see where you are at in all of this. They want to ensure that you are right where they left you, they want to see if there is someone new in your life and yes, they want to see how you are going to react to them and their nonsense. They do this quite frequently throughout the crisis. Just leave the door ajar and be civil if he contacts you. Treat him as a friend. You can't plan for this action because it will happen when you least expect it.
Now, focus on one day at a time and not too far into the future. Things change on a dime and give you a penny back. They don't know which end is up and will change in a matter of seconds. That's why it is important to keep your mind focused on you, your child and your job for now.
Begin reading your homework and visit the other threads. When you visit the other threads, be sure to post because others will then begin to gravitate to your threads to post to you.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.