Could I be pregnant?

Hello everyone, so I have a question. Could I be pregnant? Over the past week I’ve experienced a lot of nausea and can’t handle smell very well. I’ve been very emotional and have gotten a lot of mood swings lately. I’m honestly very confused because I’m on birth control and I had my “period” last week. Even though it was a very abnormal period, since I only had blood clots for two days. No flow, just clots. Then on my sixth day it stopped, seventh I only get two large spots of a rusty discharge. Now I have yellow discharge, but no odor. I’m so confused since I had sex about a month ago and also two days before my period. Someone please help!