Sounds as if it might be - I was told by my MW that sorting out possible SPD asap was important, so I'd second seeing someone as soon as you can. Last pregnancy I had horrible ligament pain in my groin (which I think was not SPD) and some SPD pain too, as you describe. My GP thought it wasn't SPD, the MWs thought it was, and consequently nothing got done. 
I've seen a chiropractor for the first time, five days ago, for what I think is SPD, at 20 wks. I'd like to say it worked wonders at once, but I'm still really sore and haven't noticed an improvement. I'm seeing her again in a week, and if nothing changes, I'm seeing a physio instead. Both private, I'm afraid - try to get on an NHS waiting list for a physio but it might take months. 
The chiropractor said she could possibly treat the symptoms of SPD but not the cause, which is relaxin flooding your system and making you hang loose! She also gave me some sensible advice -
-plastic bag on car seat to make swivelling in and out with legs together easier.
-sit on upright chair whenever possible, using a wedge cushion, maybe.
-turn over in bed by bringing knees up together and turning them with legs closed (Very important!)
-sitting on the bed to put on trousers, tights, etc.
-Avoiding pushing heavy buggies or trolleys (HA!).