When to start clomid with an irregular period

Patient: Ok so i had my period january 7th to the 12th irregular cycles arent that uncommon for me. Then about two days ago i started spotting then last night i got more blood just like my period. The thing is next month i wanted to start my clomid tablets but now im wondering what if i dont get a period next month?Should i start my clomid tablets today (cycle day 20th)? Or not?