Antihistamine & VFP?

So my husband and I have been trying to conceive baby number two. I started testing at eight days past ovulation. All have been negative. I got sick about a week ago and I have been on allergy medication, antibiotics, & steroids. My period started three days ago but it was pretty light and creamy and it’s already over. My boobs have been super sore which is what happened the other time I was pregnant. And I’ve been so exhausted lately. And I went ahead and took a test tonight and I got a very faint positive?? I’m so confused. I am aware that my light bleeding could’ve been implantation bleeding. And maybe I ovulated a lot later than I thought? But then I googled it and it said antihistamines can also cause false positive pregnancy tests? Has this ever happened to anyone?