I've got a cell line with a gene that gets bigger exponentially.

I cultured the cells from 16/1/17 for 295 days and the gene expanded exponentially. For the second culture, cells from culture 1 frozen on 22/5/17 (d127), were thawed on 2/1/18 and cultured for 196 days. For the third culture, cells from culture 2 frozen on 1/3/18 (d59), were thawed on 7/5/18 and cultured for 64 days.

Curve estimating in SPSS gives

C = 121.10 x e^(0.000547 x d)

Where C is the gene length in days and d is the number of days in culture. r2 = 0.989, p = 7.65E-26.

When you plot them on a graph, taking d0 as the starting date of each culture, they intersect at 109 on the y axis, which I know is the original gene length.

Can I please ask a) is my interpretation of the intersect correct, b) is my explanation of the data in the correct nomenclature?