Is There A Possibility Of A Miscarriage Or Pregnancy?

I Thought I Was Pregnant A Month Or So Ago Because I Had Unprotected Sex 15 Days After My Period, And When My Period Came It Came A Day Late And Then Only Lasted Like 3 or 4 Days , But It Was Heavy Like My Normal Period , And Then Two Weeks Later I Got My Period Again, And It Lasted Like 3 Or 4 Days , And Then Two Weeks After That I Got My Period Again And It Lasted 4 Days , And Now Its Been Almost Three Weeks , And I Havent Gotten It, Whats Going On .? Am I Pregnant ? My Boyfriend Said I Had A Miscarrige , But .. I Still Could Be Pregnant, Because Ive Beem Having Unprotected Sex Lately.. And Please Dont Judge , Im Being Careful . He Pulls Out , But There Could Still Be A Possability.