I have had a weird menstrual cycle story for about 4 months. Month 1: Spotting. Month 2: Spotting, and started Lo Loestrin Fe oral birth control. Also had to take Plan B morning after pill, spotting after that, as well. Month 3: No period. Month 4: No period. From month 1-3, I lost 10 pounds. I am kinda close to being underweight. My BMI is 19.0. I have done dozens of pregnancy tests throughout these 4 months, all negative. I've also had 2 clear ultrasounds. What's up?! Am I okay, or should I be worried?