Worried

So I went to the bathroom after I got home from work. I wiped and there were small amounts of light pink blood. Only happened the one time the rest of the night. I had light cramping and medium back pain ( when I have my period my back hurts the whole time I have cramps).  Today I go to the bathroom again and the same thing and it's gone again. Today just mild cramps and no back pain yet. My husband is worried and wants me to go to the ER but I know you should only really go if you bleed enough to soak a pad in an hour. Is it normal? I mean I haven't had anything like this with my last pregnancy or since this one began.