Progesterone suppositories!

Went to my last visit a week ago,at 7 weeks and 4 days,saw and heard heartbeat and saw baby had grown compared to the week before.anyway before this visit I had blood work to check my hcg and blood type,everything fine. Then this time the doctor ordered more blood work to check hcg,blood type,and progesterone levels,I got my results today and progesterone level is low and was prescribed progesterone suppositories. Anyone else had similar situation? Anything I should know or be aware of? side effects? What do you think? I’ve never had to take this,not even with my first pregnancy. I just want my baby to be ok and I’m a little worried now,Thank you