help - insurance for baby??

AJ • Toddler mama 🙃💕
okay so here's my situation. I have tricare under my dad (baby's dad also has tricare under HIS dad but will be able to switch to Blue Cross Blue Shield through his work when baby is born next month). so our plan is to put the baby under his insurance when that goes through. my doctor advised me to get Medicaid as a back up for the baby so I called the Medicaid office to ask about it and all they told me was that I had to fill out an application after the baby is born. Okay my question is... what's the point of applying for two insurances? and what if I need to take him to the pediatrician before the insurance is processed? will I just be stuck with the bill? I'm a ftm and I'm young so I'm so clueless and worried lol please help!