I Had a BA One Week Ago and Had 450cc and They Are Looking Small to Me? (photo)

Thank you for the question and picture. Based on the photograph, it seems like your plastic surgeon has done a very nice job for you.

As you can imagine, not knowing you or your goals sufficiently, online consultants will not be able to provide you with meaningful advice and/or reassurance. Your plastic surgeon will be in the best position to do so.
 Having said that, it is not unusual for patients several days or weeks out of surgery to be concerned about their breast size ( one way or another).  Often, these same patients are very happy several months down the line. Therefore, I would suggest that you continue to be patient, continue to follow-up with your plastic surgeon, and evaluate the end results of the surgery performed 3 to 6 months from now.
 Best wishes; hopefully, you will be very pleased with the long-term outcome of the procedure performed.

It is early to be assessing size. The implants will settle over the course of 3 months or so, and will fill out the lower breast while decreasing the fill above the breast that is apparent. 

I would consider 450 cc to be rather large. Since there are no fixed cup size definitions, I hesitate to guess sizes, but many on this site estimate a cup of size increase for every 150-200 cc as a rough guideline. 

From a surgeon's perspective, these appear to be well positioned, and should end up with a nice contour. Whether these will seem too small only you will be able to answer, but do have some patience. 

All the best. 

You will likely get a little smaller as the swelling resolves, but not much.  From the photos, the implants appear to be sitting up a little high as expected at this stage.  They will usually drop or settle with time and give the breasts a fuller appearance.  Time will tell, be patient.  As for bra size, this depends entirely on which manufacture's bra you wear, just like your dresses and shoes.  They may not be the same from one brand to another.