Trying to have another baby!!?

My husband and i are trying to have another baby and im suppose to get my period either on the 16th or 17th of aug and we are both hoping that i am pregnant. Should i just wait until i get a period or should i wait till the end of this month to take one?? As of right now i feel fine but then im worried that i might get my period cause i feel a lil backaches here and there but not as bad as when i do have my period, i know its normal to feel like your getting your period when your really not....I just dont want to be dissappointed...We have been trying last couple of mths and this whole mth as well.