My friend didn't know till she ran to the toilet one morning with a upset stomach, she presumed- quite wrongly as it happens!- that the beer and curry the night before were taking their natural course. Unbeknown to her, baby was well and truly on the way!!!
She did put weight on, but she believed this to be an excess of beer and late night take aways, she also continued to have her periods.
When she was grilled afterwards by us her gobsmacked mates, she swore blind she never felt the baby move.
Incidentally- despite the copious amounts of booze by the mum, the baby was perfectly healthy, Thank God!