Becoming a mother!!

Hey I'm going to tell you abit about my story.. I have a 4year old son he's 5 in oct, we trying for our 2nd baby only been 3months hoping take about 6months as that's how long it tuck to get pregnant with my son after stopped depo injection.. When I was trying for my son I didn't worry about anything getting pregnant or my pregnancy my son was born 7wks early emergency c-section spent 16days in special care.. Now I'm trying again I'm more worried about everything maybe because I've already done it once I know what to expect now and scared of having another early baby.. So thought ask everyone else with children or without what your worries are becoming a mummy? Xx