Kate I would be very careful if your pregnancy tests have started getting darker again or the my went negative and are now back to positive. It could be a new pregnancy but, and I don't want to scare you, but I would be worried about partial molar. That's where the pregnancy tissue can effectively grow back, which will start putting more HCG back into your system. They're very, very rare and I might have misread your situation, but I would be asking some questions and not let myself be fobbed off if I were you.
Loki so glad it went well for you! My poor DH- we had about a week when I felt okay to do it after 9 weeks of nothing and then I ovulated much sooner than I thought I would and am now really uninterested due to hormones!