Long periods and strange tightness?

I'm not quite sure what is wrong with me but my periods in may and June were very long (10 and 12 days respectively) and very light, mostly more like spotting than an actual period. I had an appointment because of this in July but I found out I was pregnant so my doctor said my periods weren't anything to worry about and made the appointment with a midwife instead. Unfortunately, I ended up losing the pregnancy so I asked my doctor if my weird periods could have anything to do with it and she said no, if I was able to get pregnant in the first place I shouldn't worry and that losing the pregnancy should sort of "reset" my cycles and make them more normal, which seemed like the case and first. I had a normal period in August, my doctor said that my husband and I are OK to try and get pregnant again and then in September I started bleeding 9 days before my period was due. It was just spotting for about a week and then about three days ago it got heavier, like a normal period, except I've now been bleeding for 10 days. I started out using panty liners because it was so light, then moved to tampons as it got heavier but I've been noticing that it hurts to take them out ( which has never been an issue before) and today it sort of felt like I was too "tight" to even put a new one in.

I talked to my doctor about my weird periods and he told me it was just stress. Could that be the case for everything? I've never had this problem before and I'm starting to worry...