Could labor be coming soon?

I've just noticed a few changes & I'm wondering if this means it's coming soon?  I've had lots of pressure the past couple days down low, sometimes when I stand up I feel like he's going to fall out, lol. Also my back pain has increased a lot. It's all day every day. & (Tmi) I've been constipated my whole pregnancy because I have to take an iron supplement & the past couple days I've been having really easy bowl movements, witch isn't normal for me. Last night I woke up extremely hot, & cranky, I couldn't get comfortable & I just wanted to cry. Lol. His movements have changed to me just feeling him squirming around, also I can feel him moving really really low. I'm just curious if this is just me getting further along or if this is labor approaching ?!