Opinions

I’m almost 31 weeks and I went to take a bath to ease some lower stomach pain and when I used the bathroom before getting in I noticed that I also have some light bleeding. When I wiped there was enough blood to tint the toilet paper pink. Anyone know what could be causing this? I have a 2 year old and an almost 1 year old I take care of. My youngest can’t walk yet so I carry him wherever we go and I lift my 2 year old to help her in and out of her room and my vehicle every day, maybe lifting their weight could cause it? I do have a appointment Monday with my doctor.