Boobs are aching!

Is it normal that my boobs only hurt when I put my bra on, and occasionally while I am in bed without a bra.  Somebody told me that they should only ache while the bra is off and now I am confused! Am 5 weeks and 4 days and boob ache is the only symptom I have, I keep waiting for more symptoms but it ain't happening which makes me think something is wrong!