I may be pregnant but im on the implant! HELP PLEASE

Patient: Hi there, i have had the implant in since 13.10.10 and i usually come on my period every 3 months… I do not think i have been on for ages and i am scared i ay be pregnant! I have had a few symptoms like: Feeling ill, Needing the loo more, Headaches, Back ache, Tiredness and i have been needing to drink more! do you think this is normal or should i take a pregnancy test! im really scared.