Early labor signs?

Hey ladies. I am 37 weeks today. So happy to have made it to full term.  I have to work until the very end, so I am praying for any day now. I have noticed some changes and need advice on how early these things started for you. First I have been constipated the whole pregnancy now I can't stop pooing.  Secondly I am having period type cramps ( not regular or timed. Just in general and pretty intense.) Third I had meconium come out of my nipples last night after my bath!! Clear slightly yellow tinged. I was squeezing my boons because they felt unusually sore and sure enough. Nipples were producing! Advice please :)