i keep getting headaches and feeling very sick with them. is this normal?

my baby is now 4months old and he doesnt sleep right through and i wake up alot during the night.. im not sure why i do, then after my baby has a feed he goes right back to sleep, but sometimes it takes me a while, then in the morning when i have to get up at 6:30am with my partner being at work and 4year old being at school.. i feel really tired, have a headache, and feel very sick!! the headache tends to wear off as the day goes on, ocasioanlly get a few pains during the day, the sickness comes and goes during the day. i did seriously think could i be pegnant! im on the pill... but we all know there is always a chance, so i tested but im not. but the headaches and sickness have been going on around a few weeks to a month.. at first they were every few days, now they are almost everyday. they arnt painful but annoying. im starting to get worried its something more than tiredness.... does anyone else with a baby who doesnt sleep right through feel like this??????????