Pay close attention.
This is what you do.
If you want to be absolutely sure you wont break through the ice.
Buy a long handled axe.
Chop the ice as you are walking. A good swift chop.
That should penetrate about 2-3 inches.
As long as the axe doesn't go right through, proceed.
When you swing the axe and it goes right through, stop. It is no longer safe to proceed.
I was taught that by a dear friend of mine, awhile back.
We kept going even when the tip of the axe went through and the water seeped up through the crack the axe made. But when he chopped and the axe went through easily, we turned around and went home. The next few days of cold was enough to freeze the river sufficiently to go safely. When you are fishing on 2" of ice, the water comes up slightly out and around your fishing hole as you approach it due to your weight. It is a bit unerving, but hey, you're the one that wants to go out fishing early in the season. Usually the fishing is quite good at first ice.