Squig: I would say the same as Hope. 2 days can't hurt, but on the other hand it could help (check the use by date though, just in case).
My own doctor had growth restriction issue in all her pregnancy, she lost one when only on aspirin, but the other ones were successful with aspirin and clexane combined.
On the other hand, a friend of mine had the same problem, and baby and mum were fine afterwards with just aspirin.
Hth.