Suggest Treatment For Delayed Menstrual Periods And Stomach Pain

Hi. I have been suffering from severe stomach pain for the last week along with the feelling of wanting to be sick but nothing coming up, i have a contraceptive implant and havent bled since december, my periods are usually regular and have been for the last 2 yrs with the implant in. i have taken 2 at home test, both negative. please advise. thank you