You can carry on your PA license for up to 6 months after establishing residence in Ohio. After that, you must either have an Ohio license or a license form a state that has a written reciprocity agreement.
See ORC 109.69 (B)(1) and (B)(2)
(B)
(1) If, on or after the effective date of this amendment, a person who is a resident of this state has a valid concealed handgun license that was issued by another license-issuing state that has entered into a reciprocity agreement with the attorney general under division (A)(1) of this section or the attorney general determines that the eligibility requirements imposed by that license-issuing state for that license are substantially comparable to the eligibility requirements for a concealed handgun license issued under section 2923.125 of the Revised Code, the license issued by the other license-issuing state shall be recognized in this state, shall be accepted and valid in this state, and grants the person the same right to carry a concealed handgun in this state as a person who was issued a concealed handgun license under section 2923.125 of the Revised Code.
(2) If, on or after the effective date of this amendment, a person who is a resident of this state has a valid concealed handgun license that was issued by another license-issuing state that has not entered into a reciprocity agreement with the attorney general under division (A)(1) of this section, the license issued by the other license-issuing state shall be recognized in this state, shall be accepted and valid in this state, and grants the person the same right to carry a concealed handgun in this state as a person who was issued a concealed handgun license under section 2923.125 of the Revised Code for a period of six months after the person became a resident of this state. After that six-month period, if the person wishes to obtain a concealed handgun license, the person shall apply for a concealed handgun license pursuant to section 2923.125 of the Revised Code.
http://codes.ohio.gov/orc/109.69