Yup, I'd say stretch marks
My old stretch marks from the kids are faded now (in colour only)
but they are really quite deep, and some nearly a centimeter wide. I have a very bumpy tummy.
Are they itchy?
When mine first started coming...they were insanely itchy (the skin separating). Scratching made them worse, and helped them to spread almost like a zipper in the last months of pregnancy.
At first they are raised, but mine now are indented, so I feel the edges...do you know what I mean?
There's really nothing that you can do about stretch marks. The lotions are nice and may help to keep your skin supple. Also, losing weight too quickly...and gaining it too quickly..aggravates them, so try to keep your losses in the healthy .5-2 pounds per week range.
It's a different story when you are pregnant because you haven't got any control over how much that little one stretches your belly, aside from keeping your eating healthy, of course!
Take care of yourself, and try not to worry too much, OK? There's not much that can be done aside from surgery. But they DO fade, and I consider them a badge of honour, whether from childbirth, or a reminder of what you have accomplished and where you have come from.