I would guess that maybe you are nervous about being pregnant. It seems from your dream you might be concerned about how much impact your pregnancy will have on your life and how much of your routine you will have to change. JMO
Maybe you dreaming about it for three days means you will have triplets.
It means you dreamed about being pregnant.
If you're having signs that you may be pregnant in RL, that's all the explanation you need, really.
The fact that your life just seems to go on as usual in your dreams may mean that deep down you're actually okay with the idea of being pregnant. If it scared you, they'd be nightmares, but they're not. (Or are they?)
It just means you are ovulating. You'll find this happens every month.
Dreams are always metaphorical or symbolic. It means something big is coming in your life, but you need to nurture it for it to come into fruition.
Most of the time dreams are JUST dreams. Often they are just a recreated collection of things you have seen, thought about or experienced while awake. I expect you have watched a tv show where someone is pregnant or seen a friend who is pregnant.