Although personal use breast pumps are not safe to share, hospital grade rental pumps are approved for multiple users as long as each mother uses her own collection kit. (breastpumpcomparisons.com)
I assume you were using a multi user / hospital rental pump while in the hospital? (lansinoh.com)
Some mothers mistakenly assume that because rental pumps are safely shared by mothers that it is also safe to share purchase pumps. (lllmarivt.org)