D.B.
"Lamaze instructor hat on"
Every surgery you have causes scar tissue. The more scar tissue on your uterus, the less likely you are to conceive because it reduces the places for the baby to implant. Scar tissue makes additional surgeries more challenging because it's more difficult to cut through and it doesn't heal as well, so your risks for bleeding and infection are higher.
Without knowing the true amount and location of the scar tissue you have it's difficult to say what your risks really are. And whether they were talking about conception or a 3rd c-sect. So ASK your OB for details.
OBs are notorious for not telling patients the real risks of c-sections. Nor do they tell you that in most cases it is safer to VBAC or VBA2C than it is for subsequent C-sect. Even ACOGs new guidelines suggest a TOL for VBAC before scheduling a C-sect. http://www.acog.org/publications/patient_education/bp070.cfm