Back Work Next Week and Pregnant with Twins

I go back to work next week just doing 6 hour shifts and 12 days a month in a call centre. My son is 10 1/2 months old and I m going back to work being 5 months pregnant. My son has been going to childminder for the last month a couple of days a week and this week went to her the hours I will be working, so do not have that worry. Bit scared to go back as I have not seen anyone from where I work for months, and they are being very slow at sorting stuff out for me ie going of on mat agin, confirming my holidays etc. Whem I finished work they were being awkward with my appointments and taking extra toilet breaks so not really looking for to it, just really going back to mat leave etc again. Also only working a few days in August as I have holiday booked, and will quite poss have to start my leave early due to being pregnant with twins. Oh well will update you all next week, wish me luck xxxx