Pregnant on birth control??

I’m 45 days late. I’m on nexplanon but we don’t use any other method of BC. We had sex last night and today I’ve been having sooo much discharge. Not just today but the last couple weeks. It’s like I pee my self a tiny bit but it’s like a watery milky tinted discharge. The way it dries on my underwear is kind of yellow and idk why. I know for a fact it isn’t an STD so that’s not a possibility. Does the discharge sound like pregnancy? Or just because I had sex last night? We have sex at least every 3 days but I just feel like I’m having more discharge lately.