Extreme fatigue during 3rd trimester !!

[mamaandthegirls]

I'm 29 weeks today and have the worst fatigue ever. I have a 2 year old already and she's constantly pestering me to play but I just need to collapse on the sofa all the time! She wants to be outdoors but I can hardly keep my eyes open past 11am! I went to bed at 9pm last night, woke up by DD at 8am so thought I would feel refreshed, but I feel worse
This heat doesn't help, nor does the weight of carrying a baby in my womb! Anyone got any tips to stay awake? Or why I feel like this? I'm due to get my iron checked on Monday, so I guess it could be that perhaps?

Similar situation at 28+2 weeks with a 2yr old. I think it's just the extra weight, lack of sleep partly due to heat but 2yr old alone is enough to wear out someone who's not pregnant, I'm forever going up and down stairs to empty the potty. Find myself wanting to sleep at work on the days I'm there, nothing seems to help.