Spotting at 29 weeks- should I be worried?

I’m wondering if anyone has had a similar experience and can offer advice. Earlier this week I noticed very light spotting. I reached out to my midwife and she told me to come in and see if it was cervical irritation or if not she would send me for an ultrasound. None of the probable causes were applicable though- no recent sex, no uti or yeast infection symptoms etc. When I went in she she said my cervix looked irritated and it was a yeast infection. Two different times I told her I don’t think I have a yeast infection I have no symptoms but she was convinced and sent for a prescription.

Sure enough I got the results back three days later and I never had a yeast infection. The spotting stopped though so I thought I was fine. Now last night my husband and I had sex and I woke up in the middle of the night to much heavier spotting. I understand sex probably agitated it- but should I be concerned that it is still occurring since I got no real answer the first time? Or is this normal? I’m nervous because I don’t feel like I’m getting any good answers from my midwife. Thank you for any insight!!!