Thanks for posting your query at DoctorSpring.com
See firstly, taking a pregnancy test after an abortion can be futile.
This is because the test can take upto 8 weeks to normalize.
After a Depo shot, it is normal to have erratic spotting and bleeding.
I realize that this can be frustrating.
To have a clear cut idea, please go for a pelvic transvaginal ultrasound scan, to know if this is a fresh pregnancy or just a positive test from the prior abortion you had.
All the best
Please feel free to discuss further.