help needed

Minakshi

currently my 10 weeks are going on .. at my 9 weeks of pregnancy ultrasound baby measured fine with 166b/m .. but my cervix lenght is 3.3 cm .. doc just want the cervix 3.5 cm and he took me to the progesterone supplements (vaginally) . l am just concerned that 3.3 cm cervix is a thing to worry or I am just over concerned about this thing .. is that progesterone gel makes any side effect to my baby ?? please help ..