I Had A Miscarriage On December, After The Bleeding Has

I had a miscarriage on December, after the bleeding has stopped, my husband and i made love frequently. On January 17, about 8am, i noticed blood stain in my underwear which i took to be my period and i used a pad but it wasn't as normal, little may come out now and stop then drop again after an hour or two but around 7pm, the flow became normal and it lasted for 5days. On Feb. 13, it appeared again and the flow was alright. But on march 12 about 9am, i spotted light brown blood so i squatted and dip 2 fingers into my vagina and i came out with a light brown stretchy mucus, after some hours i felt a little drop.it was just drops that day and through the night that the pad i used since i spotted it till the next morning was not full. We made love that morning and the flow increased to normal but stopped the next day. This April also, the flow was little and lasted for 3days. I did pregnancy urine test last month and it was negative so i don't bother doing it again till now. What could be wrong or could i possibly be pregnant?