Nightmares :(

Please is anyone else out there suffering from nightmares? I'm five weeks one day and last night I dreamt I lost my mum when a fleet of boats sunk. Every night for three nights before that I dreamt my boyfriend was cheating on me and the dreams all seem so real. I haven't changed anything I can think of, other than pregnancy and taking pregnacare. I seem to be having my biggest fears when I sleep and it's really upsetting me and scaring me!