IUI with Gonal F

We are doing our first IUI this month and I’ve been taking Gonal f each evening via injection pen as prescribed. Tonight was night 6 and when I pulled the pen out a tiny drop of blood when back up the needle and is now sitting in the cylinder of liquid 🤦🏽‍♀️ I’m assuming this pen is now useless? I only have one more dose to do and I don’t want to waste money on another pen! Will phone the clinic in the morning to discuss, but wondered if any of you have had a similar issue?