PREGNANCY OF UNKNOWN LOCATION(PUL)

Tiada kantung/positive UPT. Hi Mommies, nak tanya this is my second pregnancy (i hope so). But I tk sure i pregnant ke tak, i lambat 2 hari from menses. I did upt and faint line shown on 4 test kit. I used clear blue and shows a strong lines instead. I went to the doctor to get confirmation, however no sac/kantung shown via TVS (vaginal scan) . Kalau ikut kan im 5w along. However, doc asked for Me to do another test in 3 weeks time. Since ive shown no symptoms of ectopic pregnancy. No bleeding shown as well. I do have lower back pain, tender and swelling breast. All symptoms i had during first pregnancy was there except implantation bleeding. I’ve been going through so much reading that it may be a chemical pregnancy/ miscarriage. Should i be worried? Thank you moms 💗