What Causes Bubbles From Vagina Post A C-section?

I had a c-section 3 months ago and since then, after sleeping on my right side most nights when I stand up in the morning, I have bubbles coming from my vagina for like 20 seconds straight and when I urinate I can push more bubbles out until it stops. This does not happen everyday. There is no foul odor and perhaps a slight really light discharge with no color. What could be wrong with me?