separation of your rectus abdominus is called diastasis recti. it's easy to check yourself for this. just lay flat on your back, and then do a little 'crunch' where you lift your head and shoulders off the ground a bit. use your fingers to press gently down the mid-line of your belly (this will follow your linea negra if you have one). some separation is expected/normal, but if you can fit three or more fingers in between the two muscles, this is considered a diastasis. sometimes this looks like a ridge that pokes up between the two muscles, other times the tissue will dip down.
to protect it, or to keep it from getting any worse, try to avoid things like kicking up to seated from lying down, or otherwise pushing out with your belly/using your abdominals muscles to pull yourself up/etc. also, if you do find you need to do that for any reason, pull your transverse muscles in first (the girdle-like muscles that wrap around the belly) to hold the rectus abdominus in place.
all that said, i don't know that a diastasis would cause the radiating pain you are experiencing. it seems like it is more likely to be related to the pubic symphysis issues you're having than anything else.