feel good about yourself is number one. lots of mothers lose interest in sex. if you eat right and get exercise and feel good about you then you should be ok. AND get sleep. no one wants sex when they are tired. maybe plan REAL date nights like dinner out or something while a family member babysits. i doubt birth control pills affect your drive.
and maybe you need to mix it up with porn. or just ease into it like make out sessions without full sex. as if you are a teenager etc. i dont think you are that unusual. if you have a good drive before the baby i am sure it will come back.