Bug Spray equals bad idea...!!! You can get PH test strips at Wal Mart, but I would whip the yellow pages out and find a garden/Hydro store and you will be in a candy store.
Dutch Masters has a femanising spray I believe and there is one other I herd about yesterday, if you are really going to get I can take the time to look it up, but if you are just going to let your plants seed then you probably dond't need to worry too much about it now.
Adieu