Yeah i would take a poundage scale and see exatcly what your pulling first and then from there check to see if you are using the right spinned arrows. Depending on what brand you have you can look it up on the internet and see the correct spine to use versus poundage. most manufactors will have a table or chart on there website telling you this.
After that is done i would recomend taking it to your nearest bow shop and getting it tuned(should only cost about 30 bucks or so).....u probably need to do this because you changed the poundage and that throws of everything.....you will probbly also have to ree sight your bow in