Then your off to Methotrexate by injection or pill.

FORBES: Xeljanz, A Cheaper-But-Expensive $25,000-A-Year Pfizer Pill For Rheumatoid Arthritis, Gets FDA Green Light

If the HCG level remains high, you might need another injection of methotrexate.

CNN: Ectopic pregnancy

If the ectopic pregnancy is detected early, an injection of the drug methotrexate is sometimes used to stop cell growth and dissolve existing cells.

CNN: Ectopic pregnancy