19 weeks pregnant twins ! It hurts when I stand up ?

Sonja
Lately for the past week or so when I stand up or try to cook or clean I get extremely faint and it hurts. Today I was outside standing talking to neighbor and I felt like I had to throw up and got light headed. Only time I feel good is wen I'm laying down .walk and standing is becoming a task. Is this Normal with twins at 19 weeks?