I am very constipated

I have not had a bowel movement in a week. At this point I have back pain/cramps from it. Have no appetite & im also 33 weeks pregnant. I went out and spent $20 each on a bottle of citrusel and colace (2 in 1) laxative/stimulant. Which did nothing. I drink so much water, tried coffee and I’d do anything at this point to be able to use the bathroom. I messaged my provider and they just want me to go buy more pills and waste more money. Someone please help