Hello
Welcome to HCM forum
If you have a history of an ectopic
pregnancy and having no sac in utero with positive blood tests , there can be a possibility of an ectopic pregnancy this time also.
Sometimes the sac is not visible due to an early pregnancy.
Pain can be due to previous surgery or fresh ectopic .
Repeat an
ultrasound , TVS scan would be better.
Consult your
OBGYN as soon as possible.
Best wishes