Baby doesn't turn his head straight

FTM here. My son is 3 weeks today and I've noticed that he mostly preferres to lay his head on his right side, sometimes I can get him to lay his head on his left side but he doesn't seem to like it much. He also doesn't really turn his head straight forward. He will look at his toys but very rarely actually then his head straight to look up at the ones that are dangling right over him. He does hold his head up when laying on his tummy and can turn it from side to side when on his tummy. But when on his back he almost never turns it straight. Should I call his doctor? His next visit isn't until September and I'm worried. I'm attaching a picture of how he normally lays in his bassinet with his head to one side (sorry for the pic, I was making an Iron Man joke that I sent to my hubby lol). Is it a concern that he doesn't really move his head to the "straight" position?