Nick and the Candlestick by Sylvia Plath

While reading Sylvia's Bio I thought her poems would be really interesting and I would be able to read them well and understand what she was talking about. Her poems didn't make too much sense to me, but the one that I understood the most was Nick and the Candlestick. Obviously she is talking about her son Nicholas. To me it seems like she is writing about the birth of her son and how she brings him home. "I have hung our cave with roses, With soft rugs-" I took this as the part where she brings Nick home, she is referring to our cave as our home. "You are the one Solid the spaces lean on, envious. You are the baby in the barn." I thought this as Nick was the baby home in the barn. Earlier she also says "O love, how did you get here? O embryo" I thought this was Sylvia talking about how this child came into the world, but really knowing how he did. I'm not sure how the candle fits in though. I could be completely wrong with this too, but this is what I thought!