I am 8 weeks and down 12 lbs. My ob said it is fine as long as I am getting the nutrients my baby needs to grow. And it is actually safest if I maintain my weight throughout my pregnancy instead of gain since I am not skinny by any means. :)
As long as you are eating healthy and regularly and taking your prenatals you are good loosing weight could be good for you and your baby being over weight can put you and your unborn at higher risk if it becomes a big concern for you bring in up to your ob they will give you a professional opinion i wouldnt be worried though praying for you and your unborn you are going to have an awesome pregnancy :)