Do you know your blood type? Well, I thought I did until last week. And since it’s especially important when you’re 28 weeks pregnant (ever heard of RhoGAM?), this was a problem.

When you’re pregnant with your first child, you seem to be obsessed with knowing what’s happening to you week-by-week. At least I was. This time around, I haven’t even broken out my “Great Expectations” book. Instead I got hi-tech and sporadically check my Expecting iPhone app and even more sporadically look at Babycenter.com.

It was at Babycenter.com’s site that I decided to read up on my 28th week a few days before my doctor appointment. It was here that I discovered I was actually in my THIRD AND FINAL trimester (which cracks me up since last pregnancy I counted the days until I reached each trimester). Then the day after my appointment I ventured to the site again for no real reason but boredom, then read that women with a negative blood type may receive their RhoGAM shot at 28 weeks. (If you have no idea what I’m talking about, take a second to skim over this.)

Wait a second. But I’m Rh Negative (O- to be exact) and they didn’t even mention the shot! I remembered getting the shot with Big Roo both at 28 weeks AND after he was born since he had a positive blood type.

So thinking the doctor forgot, I called to ask the OB nurse and things got more confusing.

She calls me back a couple of hours later. Even through the courteous hi-how-are-yas, I can hear her voice dripping with confusion. The lab results showed I’m O+ so there’s no need for a shot. I assured her that I received the shots with Big Roo and as she flipped through the patient history sent from OB in Phoenix, she confirmed that indeed I had been marked as having O- blood and received all the shots as any O- pregnant lady would.

Funny thing is that I remember sitting in the doctor’s office being told my blood type was negative last pregnancy. I whipped out my old blood donor card and pointed out that it said I was O+. They chalked it up to a typo and I honestly never thought too much of it. After all, typos happen.

Faulty blood tests apparently happen too. A couple of days after speaking with the OB nurse, she calls me to say she flagged down the ACTUAL lab results from Phoenix and get this: my 2006 bloodwork says O+ and my 2007 says O-. Um, who didn’t catch this before now?

So last Wednesday, I had to pop into the doctor’s office again for yet another blood test. At this point I was pretty sure I was indeed O+ but we may as well be certain.

Today I got a call from the doctor’s office. The results were in and I was FOR CERTAIN a pregnant lady with an O+ blood type.

Sheesh!

I had a couple of people ask me if I was mad as hell that my old OB got it all wrong a few years ago. Honestly, I’m a little irked but nothing really more than that. I was told that it wasn’t damaging to get the shot when I didn’t need it. The biggest proof of that is Big Roo, who’s healthy and smart as can be. I mean, how can I be angry at something that happened three years ago and didn’t cause me any lasting damage?

I guess the lesson is to trust your gut, however quiet it’s whispering. The blood donor card said O+ so even though I did ask about it, I should have pressed further as to why it would have been different. Call the blood bank. Or ask for a do-over on lab work. I didn’t do either and it’s only three years later that I got it straightened out.

O+, O+, O+.

I surely won’t be forgetting my blood type anytime soon!