I've never been pregnant but back in 1999 - it seems I had a phantom pregnancy - I had sore, swollen feet, morning sickness, frequent urination, constant burping (classy) and indigestion. However I did not have sore swollen boobs nor food cravings. My symptoms were so marked that my mum thought I was pregnant but if I had been it would've practically been a virgin birth!! - put it that way!!!
I've researched this topic and it seems that there is no 1 accepted cause of a phantom pregnancy, but at the time I had mine - I'd just met this guy and had an extremely strong infatuation for him which never developed into a physical relationship. I felt that because my attraction to him was so strong that it triggered something in my brain to sort of 'get me used' to what being pregnant feels like if it ever were to happen. I told my friend at the time 'Oh I woke up feeling sick this morning, d'you ever get that?' she'd already had a baby and she replied "Oh well, at least when you get pregnant, you know you can cope with morning sickness!!" I feel this goes some way towards confirming my theory.
In my experience, the 'phantom pregnancy' wasn't pleasant in terms of me having to disappear to the toilet during working time 'cos I was convinced I was going to be sick, swollen painful feet to the point that eventually I couldn't get my shoes on and had to wear trainers in work! and terrible indigestion where even eating a packet of crisps would cause me to do a series of massive burps!!
However, that said, it wasn't absolutely MASSIVELY unpleasant either in the sense that I felt it gave me at least some idea of what a pregnancy would be like!!