Is this normal?!

Alexis
My baby was due June 15th, he was born 6 weeks early on May 5th at 3lbs 10oz, due to severe preeclampsia. He had zero issues breathing or eating, he just needed to gain weight. He is now 7 weeks old or by "adjusted age" 1 week old and about 7lbs and he just rolled from his belly to his back, twice! With no help.