Concerned and need help!!!

So I am about 13 DPO. Yesterday I had a very faint line on a first response test. I have experienced back pain the last two days and bloating! Yesterday my stomach felt like I have been doing sit ups and my boobs have felt like punching bags (strange analogy..I know). This morning I took a test expecting it to be darker and it was lighter? Has this ever happened to anyone?? By glow I'm about 13 DPO but this past Monday I had a lot of EWCM. Could I have ovulated late and really only be 7 DPO and it just be really early or is this a chemical pregnancy?? I also have checked my cervix and its lower and soft and somewhat closed...but I can never tell if it's closed or open because I can always feel the opening. If anyone has experienced this or has suggestions that would be great!!!