Hello ma'am and welcome.
At times, some women continue to twst negative for various serum and urine pregnancy
tests, despite of being pregnant, but this was confirmed with the help of an ultrasound
scan. So at 4 months, if you are indeed pregnant an ultrasound can confirm it.
But in my opinion, your presentation is most probably due to a hormonal
imbalance which you have a history of. Please schedule an appointment with your doctor for an accurate diagnosis and management accordingly.
Hope this helps.