My husband and I started IVF this summer as we have been trying to get pregnant for 4 years now. There seems to be a problem with both of my fallopian tubes but that hasn't been confirmed. On 31 May this year I had embryo transfer. On 14 May I had a negative pregnancy test and I started my period on the same day. Was disappointing but we had already decided to move on to the next attempt later in the year.
A month later as usual I got a second period which has lasted now for around 3 weeks. For the past 2 weeks I have been getting brown spotting. It's a light steady flow, no clots (sorry TMI) and no pain at all. I rang the fertility clinic 2 days ago just to put my mind at rest that this is normal after IVF and was told to do a pregnancy test.
I got home and did 2 that were both positive! We were in shock and tentatively excited. Yesterday the clinic called us in for a same day appointment where I did another pregnancy test (positive line barely there), an internal scan (showed nothing) and a blood test.
The blood test showed I have at some point been pregnant but it is unclear as to whether I am currently miscarrying (which I almost certainly am) or I'm in the very early stages of pregnancy. I have been asked to do another HPT at the weekend. In truth I think the clinic are as at a loss as we are. 
Has anyone else had a similar experience and how did it turn out??