Heartbroken!!! 😭😭😭

Well today I had my heart tore in two, I've been experiencing a lot of pregnancy symptoms and I was so nervous to test. I took a first response digital test and it came back positive, super stoked went and seen my boyfriend on his break and showed him the test, he was shocked and happy. I then went to my local planned parenthood and had them do a pregnancy test, it came back negative they were confused just as much as I was, they sent me to the hospital lab for blood pregnancy test and they also came back negative. Out of every pregnancy test in Walmart I grab the defective one, My heart is completely shattered and I'm lost for words. I can't believe a test would say yes but be a lie. My step son is going to be 11 next year and we all want a new addition to the family. I really need support and opinions on what to do to get pregnant, My doctor at planned parenthood gave me prenatal vitamins to start taking, what else should I do?