thank you for your query.
As you have taken the birth control pill erratically, chances of pregnancy
definitely do exist.
Please consult a gynecologist since you have already done 3 home tests, and one of them is suggestive of pregnancy.
The symptoms you mention could be those of an early pregnancy and also pre menstrual symptoms.
You would allay your anxiety
by having a confirmation with a doctor via examination and a blood pregnancy test / pelvic ultrasound
In future, please be very particular about your pills or switch over to an alternative method.