16 Week Old Egg Laying

I bought my chickens (ISA BROWN) from tractor supply on May 24th, 2020 (I live in New England). I noticed one was starting to squat when I went near her. Looked it up, realized she was basically going to be laying eggs soon. So on the 11th of September we received our first egg. We got about 4 normal eggs out of her, and the rest have been soft shell.

She usually lays one everyday (being soft shell or hard). The last egg she laid on the 17th was a soft shell and you could see the yolk inside. But she did not lay one yesterday (Sept 18th, or this morning Sept 19th). She is the ONLY Hen laying right now (one other started crouching when I go near her too). All chickens have been eating fine, drinking fine & acting normal.

I attached a picture of the last egg on September 17th.

Is this too early for chickens to be laying?

Should I be worried she is egg bound?