supply issues at 6 months?!

MelissaFSU

My DD will be 6 months next week and until now, breastfeeding has been going great.  I work full-time so she gets 2 bottles during the day (I feed her at lunch) and usually I pump around 5 ounces in 15 minutes.  This week I'm getting 2.5oz after pumping for 20 minutes.  DD seems fine when she eats at home and isn't acting hungry so I'm confused.  Is this a normal 6 month thing, do I have a real supply issue, or am I starting to not respond to the pump?