Be patient. I typically tell patients not to expect to see much until 6 months. However most of the growth happens between 6-9 months.
It can take 6 to 12 months after surgery to see results. If you are concerned it is best to contact your doctor
I would greatly recommend you not to judge the final results at the 6 month period. It can take over 1 year for you to see the final results.
You must wait at least 8-10 months to see the full benefit of an FUE transplant. Then you could go back to your doctor and ask questions about growth if there is a problem.
I would give it another few months before making the final decision - to be honest, it looks fairly sparse along the hairline and you may need a few more grafts to help fill in and give you the density you would like. But give it time, while most patients by 6 months we have a pretty good idea on what the hair response and yield will be, sometimes it can take 9 months and even longer. are you using minoxidil/laser caps/propecia? where were you before the transplant, and how did it look immediately after? there are lots of variables at play here, so keep you head up, and give it a bit more time.
We normally see the majority of hair growth in the first six months, with some minor increases in hair caliber in the second six months. Do you have any before photos, and immediately after the procedure photos to show the graft distribution? It seems the hairline area has come in quite thin, and will likely need additional grafting to blend in with the frontal forelock and mid-scalp hair.