I'm so sorry to hear of your loss :-(
I also lost my baby in February 2014. I was 23 weeks pregnant when I went to the scan to be told baby had died at 19 weeks. I also didn't know baby had died as I was sure he was moving still. I had to be induced and deliver our boy. We had an autopsy done and the results were uterine growth restriction.
I had the gastric sleeve in September 2012. I lost 5 stone but my weight stabilised before becoming pregnant. They said it can't be because of the surgery but I'm unsure as it seemed the midwives didn't know what the surgery was at my first appointment and lack of knowledge with the health professionals. I have have two healthy children previous.
I am now 7 weeks pregnant with twins and I have to take aspirin and lots of Vitamins everyday also scans every two weeks.
I hope you and your partner are coping ok. I know how painful this is. Still think of my baby every day.