1st pregnancy. HELP

Hello ladies,

This is my first pregnancy and I am currently 17 weeks and a day. For the past three days I've been feeling this sharp pain on my lower right side all through my back. It's worse at night or when I sit. Breathing makes it hurt as well. During those pains I get nauseous and can't eat. Is this something serious? I've already talked to my midwife she said as long as I'm not bleeding Im fine but I'm still concerned. Has anyone experienced this before?