Help!!!

so I had a miscarriage 3 yrs ago after 3 healthy pregnancies and worried I possibly had another miscarriage but I am unsure I am 14 days late and had a bit of bleeding with cramps and clots the next day which stopped then followed by off and on brown spotting for several days for almost 2 weeks with pieces of what looked like tissue unlike my normal Af I never took a test bc I just figured it was stress but tested negative yesterday however I am still not bleeding or spotting now.. either I had a chemical pregnancy or something else is going on.the hcg wouldnt or shouldn't still present if I was pregnant maybe I will never know......how would I know if it was a chemical pregnancy or not?