3rd pregnancy after 2 early losses

[Kimiw]

Well the title says it all, this is mt 3rd pregnancy following 2 early losses. A little background on me. I have pcos and heterozygous for MTHFR genetic mutation. We spent the past 8 years ttc and in August 2012 we finally had our first bfp! But that sadly ended at 6 weeks. We got lucky again in October of 2013 but that too ended at 6 weeks. Well, on 3/17/14 (St. Patricks day) we got our third bfp (luck of the Irish!). This time my doctor put me on progesterone, baby aspirin, and lovenox (blood thinner for my MTHFR). I was on aspirin and progesterone with the last but he didn't think it was enough so he wanted a stronger blood thinner. I went for an early scan at 5 weeks to see if a gestational sac was visible and wothere was! But the doctor said it looked small for 5 weeks now I'm worried

I should add that with the first two, we never got to see anything on ultrasound. This pregnancy so far is going better than last by 4w2d with the last I started bleeding.