Generally, the sutures are mostly still in place and there is some of the gums which have not totally healed and grown "back" together, which they will do in another week or two more completely. So, if you have some visible windows (small areas) that show some of the material, I'd not be worried, as long as it was very small, and the area of the graft material is not loosening or dislodging. So, I think you are likely fine, if the above is the case. Just be rather gingerly while eating, tooth brushing, etc.
I still think it would be a good idea that you call your Dentist tomorrow and inform he or she of such. Additionally, if you'd like to, you could take a picture and forward it to me to see here. Also, the same could be done and you could forward the picture to your Dentist for his approval, and perhaps save yourself from having to return to the Dental office tomorrow. Your call here!
Again though, if your material is staying place, just be cautious and gentle, and likely all will be fine. And of course as more healing occurs, and it will, you will be even better off. I hope this help you.
*Do ask any follow ups, should you have such - OK?