Losing Mucus plug

I'm going to be 25 weeks on Sunday, and this morning I noticed that I lost my mucus plug and I got scared and read that it indicates labor starting or early labor? I'm barely 25 weeks I have been under a lot of stress lately and have been a bit depressed I'm not sure if that has anything to do with it, I have been packing and cleaning and bending down and picking up boxes right now I'm having cramps and my back is aching it feels like period cramps starting do you think I'll be fine? This is my second pregnany but I didn't go through this with my first.