i've had my period practically all month?

hello,
i am 21 years old and have one child already, when i first found out i was pregnant it was because of cramping, I was only 3 weeks pregnant so i had not missed a period yet. my question is my last period was due on may 22 i ended up getting my period on the 24 it ended on the 27 then on june 9th i started spotting brown mucus (sorry for details) which then turned to blood on the 17th i woke up still bleeding and my new period was due to start. by the end of the day my tampon was clean like i didnt have my period today the 18th the same thing i was bleeding this morning but it was agan brownish pink. i had called my dr when i started spotting after my last period and they told me it was just old blood. but it lasted from the 9th until now. could i be pregnant? i took 4 pregnancy tests around the time of my last period and they came out neg. but my period is usually very regular and always the same. when should i test again to make sure seeing as ive had my period practically all month?