You should definitely go see your primary care doctor
about this. There are several potential complications that can occur after a tattoo, and your doctor can examine the area for you and rule these out.
First, some local inflammation and redness, which might include a 'bumpy' rash, is common after getting a tattoo. Generally this lasts just for a few days before beginning to subside and it doesn't usually require treatment.
However, it is also possible for a new tattoo to become infected, and in the early stages it can be hard to tell the difference between local inflammation and an evolving infection. Warning signs would include worsening or spreading redness or pain, as well as any sort of increasing drainage from the skin or fever
. If your doctor finds evidence of a skin infection, then you will likely need to take antibiotics to clear it up.
Finally, some people have allergic reactions to the dyes that are used when making the tattoo. Most commonly, this allergic reaction is to red tattoo dye, but it can occur with any dye.
Start by getting in to see your primary care dotor for evaluation and treatment as soon as you can, and good luck!