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.
Best wishes.