Mass of blood under hair transplant recipient area (Photo)

The collection of blood or fluid underneath the skin may be a hematoma or seroma, as your doctor suggested. This accumulation may need to be removed by your doctor. I would recommend scheduling an in person follow up with your doctor in order to get a proper diagnosis and to find the right course of treatment, if needed.

If your doctor believes it is a seroma it is best to follow up with your doctor for treatment since your doctor is familiar with your particular case.

Hello,
I believe your Doctor is right it looks like seroma. Do not worry about this situation, if it get worse you can start using an antibiotic just in case to not to get an infection. These kind of problems and situations can appear for the first weeks of hair transplant operations. 

Hard to say from the story and photos- sounds like a bood clot (hematoma) though this would be odd at the recipient area.  This needs to be addressed in person by a physician.

Being 2.5 weeks out from your surgery with this amount of swelling, it is time to be reevaluated by your physician and to have it aspirated and drained, with the fluid sent for culture.  You likely have a seroma or a retained hematoma, but the possibility for infection is always there, especially this far out.

Maybe you had some bleeding at the time of the surgery and this will eventually disappear over time, so don't worry