What Causes Nausea And Headache After Taking Contraceptive Pills?

hi doctor,i am 27 years old female,i want to ask u about my case,i start to take contrasptive pills from the 4th pills from the dosage and after 7days from taking that pills i slept w my husband for 3 days then he travel but i still continue the pills untill the dosage before last pill,mean to say i took from the 21 pills 16 pills,and when finish it the blood come down after 3 days but very little blood only,and now after 15 days im feeling nausea for 2days,headache,and sleepy in the morning and i notice today something white come down when i make urine,so my question is iam pregnant or no?so thanks doctor 4 u