Hi mama! Ito talaga ay best to confirm with your OB muna bago magpaturok bukas, they know your full health picture and can give you the safest advice for you and baby at 20 weeks. A few of us mums have asked our doctors about vaccines during pregnancy, at seryoso talaga sila sa timing, kaya please don't skip that consult. Mabilis lang yan, promise! Keep safe!