Hi there, we went through this with our DD when starting solids. Often new foods can be rough on such delicate little tummies. With such frequent NW after midnight I would always think discomfort, so I really think you are on the right track with your instincts here hun.
We found that baby rice cereal was a huge no go for us, made DD too gassy and constipated and generally uncomfortable. How about keeping a food diary and only introducing any new foods every 3 days or so at least? That way you can see if there is a reaction to any foods and then aviod them for a while if there is. HTHs.