Turtles don't breed after being pregant

After having found two turtles, I fed both with seagras,

One got pregnant and both went away.

I followed the pregnant one to their home beach, but it seems that it can't find it.

It went onto a beach, but didn't dig in the sand with it's feet.

After a few seconds, it swam away.

I followed it, but it always changed direction and swam away again.

Didn't seem to go directly to the home beach.

And it stayed pregnant the whole time.