Hello all mummies. I am into 7th week and experiencing headache & nauseous everyday.

Hello to all mummies. I am into the 7th week and experiencing headaches and nauseous almost on a daily basis. In addition, I am suffering from very bad constipation. For my headaches and nauseous, OB did prescribe me paracetamol and nauseous medication. I don't feel good taking them regularly, though. Any recommendation to ease them? As for my constipation, I was given Dulphalac. However, it doesn't work. So later on, I was prescribed bisacodyl (laxative stimulant). Is it safe to consume bisacodyl? Thanks in advance :)