Help pregnant with 3rd and scared

Hi I just found out I'm 7weeks pregnant on Saturday I have pcos and I'm over weight I fell natural me and my hubby have been trying for 18months I have 2 boys already but I'm so scared of something going wrong and going for my ultra sound I really don't no what I would do if something goes wrong but I'm so scared I haven't told any of my family but my mum and a friend but my husband has told everyone