bleeding and I'm scared

So the last time me and my bf had sex was almost a month ago. My period was may 3rd. We didn't have sex during my period or when I ovulated. The last time we had sex was May 18. I'm not on the pill. When we had sex we used a condom, he didn't come in me and I used spermicide. My period came on May 29th and lasted a week. Like my usual. With my bf being away, we haven't had any sex and I've been masterbating more than usual. With my toy and my fingers. Today I masterbated with my fingers. A few hours after I went to the bathroom and saw that I was bleeding alittle. Could it be because i was masterbating? I'm kinda scared this has never happened