Yes. The sun is not going to hurt your baby in anyway. Since you are more sensitive in the sunlight while pregnant be sure to use sunblock. If anything, the Vitamin D you receive while in the sun is good for you.
Laying out in the sun for you, if you are 6 weeks pregnant, is not going to harm you or the baby but the pre-condition is that your face should be towards the sun and back towards the earth.
you should not lay out in the sun if you are pregnant you could harm your baby to much son is not good for you. and if you get sun burnt you could maybe get a fever from being to hot and that could harm your baby.