It can take about 6 weeks after a miscarriage to get your period again. Because you had a surgical procedure to remove the tube and your sweet baby it might take a little longer than 6 weeks. After my natural miscarriages (non-ectopic) it took 8 weeks for me to get that first period each time. So everyone is different. Don't stress about it or think about it; it'll take time.
I agree with Joy. Your body is getting back to normal and sometimes during that process things get out of whack. It took me 2 months after both of my mc's to get back on track, And your body has gone under alot of stress due to the surgery. Im sorry for your loss.