Pregnancy before period returned

Lauren
Just freaking out a little. I'm still breastfeeding my 5 month old, we supplement probably 1 feeding per day with formula since I went back to work. I haven't had a period yet, but just clear discharge the last few weeks. I had some spotting yesterday, but it was only once. My husband and I had sex once last week without any protection, and now I'm freaking out that it was implantation bleeding. We had trouble conceiving and had an <a href="https://glowing.com/glow-fertility-program">IUI</a> for our daughter. I know it's possible to ovulate before you have a period, but is this common??? Has anyone had normal periods or spotting while breastfeeding? Please tell me I'm probably not pregnant!!