Certainly always consult a good real estate attorney for each individual situation. Dolly was correct about consulting an attorney however she has it completely in reverse regarding "Joint Tenants with Right of Survivorship".
It should state right on your deed how title was taken. Basic real estate law tell us if you took title as "Tenants in Common" you may determine through your will or in the absence of a will Pennsylvania state law will determine to whom your assets, including real property, are left in the case of your death.
If you took title as "Joint Tenants with Right of Survivorship" you cannot circumvent this through a will and the property would go to your boyfriend in the event you should pass prior to him just as should he pass prior to you his interest in the property would go to you. The exception to this would be if he was convicted of your murder in which event it would go into your estate as determined by your will.
Again, contact a good real estate attorney to determine how you took title and if it turns out that it was by "Joint Tenants with Right of Survivorship" maybe you can discuss with your boyfriend having the deed transferred form you and him as "Joint Tenants with Right of Survivorship" to you and him as "Tenants in Common" which may benefit both of you if it is also his intention to leave it to heirs other then you.