one spot of pink, very mild cramps

I am 5w5d. I have had mild to period-like cramping for the past two weeks. My doctor told me as long as they are like period cramps or less, it's just my uterus growing. I got an hcg done two days ago and my levels were 9,000 - my doctor said a very good number. However, today I had one drop of light pink when I wiped. There's been nothing since, and it was literally 1 drop. Should I be concerned?